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For Sunday - May 19, 2019 !
Here`s Sunday - May 19, 2019`s
Lowest Barometric Pressure : 29.81″ at 4 a.m.
Highest Barometric Pressure : 29.98″ at 11:59 p.m.
Lowest Relative Humidity : 67% at 4 p.m.
Highest Relative Humidity : 100% at 3 a.m., 11:59 p.m.
Lowest Dew Point Temperature : 63° at 4, 5 a.m.
Highest Dew Point Temperature : 72º at 5 p.m.
Lowest Wind Speed : Calm at 11:59 p.m.
Highest Wind Gust : SW – 29 m.p.h. at 1:06 p.m.
Lo : 64º
Normal : 58°
Record Warmest : 70º In 2013 !
Record Coldest : 38° In 2002 !
Hi : 82°
Normal : 81°
Record Hottest : 92º In 1964, 1974, 1996 !
Record Coolest : 64º In 1952 !
Rainfall : 0.11" : Daily Normal 0.17" Rain fell during the 12, 1 a.m. hours here on Central Avenue in Bemis, TN
Record Wettest : 1.21" In 1997 !
May`s Total To Date : 3.70" In Bemis, TN. Normal 3.54"
2019`s : Total to Date : 31.12" Normal 21.39"
May 18, 2018 : Lo : 69º : Hi : 90º : Rainfall : 0.08"
May 18, 2017 : Lo : 67º : Hi : 86°: Rainfall : 0.87"
May 18, 2016 : Lo : 47º : Hi : 77º : Rainfall : 0.00
May 18, 2015 : Lo : 63º : Hi : 83º: Rainfall : 0.00
May 18, 2014 : Lo : 53º : Hi : 83º : Rainfall : 0.00
May 18, 2013 : Lo : 70º** : Hi : 88º : Rainfall : 0.00
May 18, 2012 : Lo : 62º : Hi : 87º : Rainfall : 0.00
May 18, 2011 : Lo : 54º : Hi : 79º: Rainfall : 0.00
May 18, 2010 : Lo : 51° Hi : 79º : Rainfall : 0.00
May 18, 2009 : Lo : 41º : Hi : 78º : Rainfall : 0.00
May 18, 2008 : Lo : 50º : Hi : 88º : Rainfall : 0.00
West TN`s Coldest Lo 64º at Bemis, Bolivar, Covington, Lexington, Jackson, N.W.S. office in Memphis, TN, Paris, Selmer, Union City, TN
West TN`s Hottest Hi 84º at N.W.S. office in Memphis, Somerville, TN
U. S. Highest Temperature for Sunday, May 19, 2019 106º at Rio Grande Village, TX U. S. Lowest Temperature for Sunday, May 19, 2019 10º at Pikes Peak Summit, CO
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...Now that this story has achieved National headlines it looks as if people are beginning to understand how much rain can fall in California during 'extreme' events...this flooding was very devastating to many residents along the massive Russian River course...
...downtown Guerneville was virtually cut-off from the rest of the county...idee has camped many times at Johnson's Beach during the summer while he worked at the Sonoma County Fair in Santa Rosa...most of these years were in the 'drought' years...the bridge crossing the Russian River in downtown Guerneville seemed extremely high above the low lying river...the campground was in the 'riparian' area about 10 feet below the streets of Guerneville, in a grove of sycamore trees...sycamores often grow next to streams and rivers, and can take large floods...
...to see the water levels rise so high is amazing, on walks through Guerneville in those years many signs on businesses and Inns showed 'flood level' meters showing how high the water has risen in the past...it was hard to imagine flood waters rising to 40-50ft when the drought had turned the Russian River into a tiny stream that idee observed during his stays during the heat of summer(July into August)...thoughts and prayers go out to all of the people devastated by flooding in Northern California...hopefully none of the storms we receive this Spring bring such disasters.
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Doing this retrospectively using 3-2 12z model runs in order to include the 48 hr models. Cuts off a bit of Maine at the end, sorry.
If anyone has the 3-2 12z Euro snow map, please add in comments. My guess is it won't matter. I'll toss in the 3-1 12z snow map for now.
The results...they were all too far south and underestimated the precip. When we saw the radar returns heading in, we knew a foot was possible. Best axis I think is the NMM but its relative to the other models. I can't even do a poll on this cause they are so far of. We had 12" in Newtown. The HDPRS wasn't too bad, but too far south. TT maps aren't good for the southern edge for this event either.
Interestingly, the NWS two event forecast vs 2 day total looks pretty good on the southern edge. Also could be that it was still snowing in those areas as the map only went to 12z.
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QUOTES FROM WXDISCO BOARDS, AUGUST-DECEMBER 2018
. SITTING OUT ON THE SCREEN PORCH, NO "OFFICIAL" RAIN
AT THE MOMENT, BUT THE MAPLE ABOVE IS DRIPPING.
ENOUGH!!! I CONCEDE THE FLAG!!!
Lynniethelurker, from her post of 8-11-18
RIPPING RAIN HERE AND I'M NOT EVEN IN THE HEAVY
STUFF. I DON'T WANT THE HEAVY STUFF. NO MORE. WE
NEED TO PICKET THIS RAIN AND TAKE A STANCE! WE
WON'T BE BULLIED ANYMORE! RAIN RAIN GO AWAY…
JUST WHEN YOU THOUGHT YOU WOULDN'T SEE MANY
MORE STORIES OF CARNAGE AND MAYHEM OUT OF THIS
WET PATTERN - A NEW DAY DAWN AND "WHOOSH" MORE
WATER RESCUES, FLOODS, WASHOUTS, SINKHOLES.
SO WHAT WE WILL SEE IN THE FUTURE, AND THIS IS FACT
NOT CLIMATE CHANGE HOOEY, IS MORE INTENSE STORMS
DURING ANY SEASON. MORE SEVERE FLOODING, INTENSE
BLIZZARDS AND WINTER STORMS, HUGE SPRING/FALL
STORMS AND SEVERE WEATHER, PROPERTY DAMAGE AND
IRONICALLY DROUGHT. WHAT WAS A COMMON RAIN
STORM 15-20 YEARS AGO NOW DUMPS DOUBLE EVEN
TRIPLE THE MOISTURE.
Planet Master, 8-14-18
MY MUSICAL LIKES ARE DEFINITELY ALL OVER THE
PLACE. ANYTHING FROM PRINCE TO FLEETWOOD MAC TO
THE ROLLING STONES TO SLY & THE FAMILY STONE TO
AIMEE MANN TO SINATRA'S CHRISTMAS ALBUM. (ETA:
CHRIS CORNELL & EARTH WIND & FIRE ON CURRENT
ROTATION) SEE? ALL OVER THE PLACE! I ALSO QUITE
ENJOY CLASSICAL AND THE 40'S STATION ON SIRIUS AT
TIMES - A SONG ABOUT A CEMENT MIXER?! GOLD!
. BAD ENOUGH WHEN PEOPLE MAKE STUPID DECISIONS
FOR THEMSELVES, DOWNRIGHT CRIMINAL WHEN THEY
MAKE TERRIBLE DECISIONS FOR THE HELPLESS...
HUMAN OR OTHERWISE
. WEATHER IS AN AMAZING THING. ONLY GEOLOGY HAS
ANYTHING LIKE THE SAME KIND OF POWER AS WIND,
SUN, AND WATER DO.
. DOES ANYONE KNOW IF THEY HAVE EVER ATTEMPTED A
REVERSAL OF TRACKING A TROPICAL CYCLONE? TRACK
IT FROM BELOW THE SURFACE IN A SUBMARINE OR FROM
A DISTANCE IN DEEP WATERS? I KNOW NOT FEASIBLE IN
THE SHALLOWS WITH A REAL SUB, BUT WHY NOT DRONE
SUBS IN THE NAME OF WEATHER AND SCIENCE? THINK I
MIGHT HAVE SIPPED THE JUG ONCE TOO MANY...
Weather Monger, 9-13
. HIGH WINDS ARE JUST ONE OF MANY DANGERS. WINDS
ARE DIRECTLY RESPONSIBLE FOR <10% OF DEATHS AND
INJURIES IN THESE STORMS. (HEARD THAT STAT ON CBS
THIS MORNING). WATER IS THE BIGGER THREAT THROUGH
STORM SURGE AND FLOODING (RAIN). MOVING WATER IS
MORE POWERFUL AND RELENTLESS. WHEN WE HEAR
ABOUT THE PEOPLE WHO NEED TO BE RESCUED, IT’S
USUALLY A WATER-RELATED ISSUE.
Burr@Work , 9-14
. THERE ARE NO GREATER TREASURES THAN THE HIGHEST
HUMAN QUALITIES SUCH AS COMPASSION, COURAGE AND
HOPE. NOT EVEN TRAGIC ACCIDENT OR DISASTER CAN
DESTROY SUCH TREASURES OF THE HEART.
USCG AST, 9-14
SOMETIMES I FEEL LIKE THE ONLY PERSON IN MY AREA
WHO IS FREAKING OUT OVER THESE TREMENDOUS NON-
TROPICAL RAINSTORMS. WE'VE HAD 2 STORMS THIS
SUMMER WITH 7-10" OF RAIN IN LESS THAN 24 HOURS...
IT'S INSANE!! JUST TORRENTIAL RAIN FOR HOURS AND
HOURS, NON-STOP. IT'S REALLY REMARKABLE, AND I LOVE
TO DISCUSS IT WITH LOCALS, BUT IT'S LIKE THEY'VE
FORGOTTEN ABOUT IT ALREADY. I DON'T UNDERSTAND
WHY PEOPLE AREN'T MORE CONCERNED...SHEESH!!!
SORT THREADS BY MODEL......CAMP GOOFUS, CAMP
ABSOLUTE ZEURO AND MAYBE CAMP I'LL BE NAM'D. THIS
WAY WE CAN SNEAK INTO THE OTHER CAMP'S FOR FUN
THINGS LIKE SNOBAL FIGHTS SPEEDO RAIDS.
Miller A, 10-2-18
SO MUCH WATER THAT IT IS DRIPPING DOWN THE
DOWNSPOUTS. THE GRASS IS SODDEN, HAVING NEVER
DRIED FROM THE LAST RAIN, WHICH HADN'T DRIED
FROM THE PREVIOUS HEAVY DEW, WHICH HADN'T
DRIED FROM THE PREVIOUS DELUGE, WHICH... WELL,
YOU GET THE IDEA.
THE PATTERN OUT IN THE PACIFIC IS SOMETHING
IGNORED BY TOO MANY I THINK. YES, FOR COLD AIR TO
BLEED ALL THE WAY TO THE SOUTHEAST COAST AND
GENERATE GOOD NOR'EASTERS, YOU NEED SOME
BLOCKING IN GREENLAND, BUT GENERALLY SPEAKING
THE FURTHER WEST YOU GO, THE LESS OF AN IMPACT
THE NAO IS GOING TO HAVE.
MY DAD AND HIS BUDDIES ARE BIG TIME MUSHROOM
FORAGERS...THEY'RE LIKE GIDDY SCHOOL KIDS WHEN
THEY GO OUT. THEY'VE GOT BUSHELS OF MUSHROOMS
FROM THIS YEAR....HONEY, CHANTERELLES, BOLETES,
BLACK TRUMPETS, OYSTERS, HEN OF THE WOOD, STUFF
I'VE NEVER OF...POC WOULD BE PROUD. SPEAKING OF,
WHERE IS POC? HOPEFULLY OUT FORAGING TOO...
NAH JUST THE NORMAL WE GO FROM SUMMER TO
WINTER AKA 15 DEGREES ABOVE AVERAGE TO 10-15
DEGREES BELOW AVERAGE AND WINTER TO SUMMER AKA
SNOW AND 34 IN LATE APRIL TO 80 AND SUNNY EARLY MAY
IN THE GREAT LAKES AS IT FEELS LIKE HAS BEEN
HAPPENING FOR 5+ YEARS NOW
MY RULE OF THUMB IS THAT IF YOU'RE IN "THE SWEET
SPOT" FIVE DAYS OUT, YOU WON'T BE UPON THE
ARRIVAL OF THE STORM. WHETHER RAIN OR SNOW,
IT'S NEVER FAILED ME BEFORE, SO I AM SURE WE WILL
SEE PLENTY MORE CHANGES!
A BOWLING BALL STORM TRACK IS RARE BECAUSE IT
BASICALLY WEST TO EAST WITH VERY LITTLE "DRAW" TO
IT. IT'S RARE BECAUSE IT REQUIRES A FAIR AMOUNT OF
ZONAL CONTINENTAL FLOW WHICH BASICALLY ISN'T
GOOD FOR STORM CREATION IN THE FIRST PLACE. I’M
NOT SURE I'VE EVER SEEN OR TRACKED A WINTER
BOWLING BALL STORM. UNCLE LARRY CALLS IT A
SOUTHLAND TEMPEST(EL NIÑO EXPRESS).
Pocono Snow, 10-25—after this quote, I have seen numerous references to bowling-ball storms. I am still unclear exactly what they are. I think they are west-to-east systems that stay within the same latitude across the country.
WAS NICE TO SEE MICHAEL EVENTUALLY TAKE THE PATH
IT DID. THIS WAS WHAT EVENTUALLY BROKE DOWN THAT
STUBBORN (BUT BY NO MEANS HISTORIC) SE RIDGE WE
WERE ON FOR MONTHS. THIS OPENED THE FLOODGATES
TO WHAT MANY OF US WERE TALKING ABOUT - COLD
CANADIAN AIR THAT WAS BOTTLED UP. NOW THAT IT'S
COMING DOWN, AND WE'RE SEEING OUR FIRST
NOR'EASTER, IT'S ALSO NICE TO SEE THE FIRST STORM OF
THE SEASON TAKE A STORM TRACK THAT SETS THE STAGE
FOR HEAVY SNOWS IN THE MID ATLANTIC, NORTHEAST,
AND NEW ENGLAND ALL WINTER. THIS STORM TRACK
COULD BE A COMMON ONE THROUGHOUT THE WINTER
AND ALMOST ALWAYS FAVORS THE HEAVIEST
SNOWFALL (GULF MOISTURE, TRANSFERRED TO
ATLANTIC, L RIDES UP EASTERN SEABOARD).
90s Blizzards, 10-26
GIVEN THE APPALACHIANS AND THE COASTAL PLAIN
WHICH HAS THE GULF STEAM RIDING UP IT, THE MID
ATLANTIC AND NEW ENGLAND IS IN THE MOST UNIQUE
AREA OF THE WORLD WHEN IT COMES TO TRANSFERRING
STORMS. I FIND TRANSFERS FASCINATING. A LARGE
AMOUNT OF EAST COAST STORMS FROM FALL TO SPRING
HAVE SOME SORT OF TRANSFER IN THEIR TRACK. THAT'S
WHAT MAKES THE 40/70 BENCHMARK SO POPULAR, AS IT
BECOMES AN AREA WHERE CAPTURES FROM THE UPPER
LEVELS CAN OFTEN CATCH-UP TO SURFACE LOWS
CAUSING STALLS, RETROGRADES AND BOMBOGENESIS
ETC. PRETTY COOL
SHOW ME A FORUM WITH NO SPAMMERS TRYING TO GET
IN AND I'LL SELL YOU SOME BEACHFRONT
PROPERTY IN KANSAS.
Weather Matrix, 11-9
MORE RAIN. GOOD, WE NEED IT. HOW CAN THE MOSS AND
MILDEW AND MOLD GROW WITHOUT IT? THE CARPENTER
ANTS AND TERMITES NEED SODDEN WOOD TO EAT.
TO ANY GUESTS BROWSING THIS THREAD, PLEASE TAKE
THIS AS AN INVITATION TO JOIN UP AND HOP IN! WE ONLY
BITE ON DAYS ENDING IN THE LETTER "Y".
The Day After Tomorrow, 11-14
THE MYTHICAL BACK-END SNOWS! I HAVE THAT ON
MY BINGO BOARD!
Ryan Duff, 11-14
DON'T TELL THEM THEY SUCK THOUGH. THEY WILL GIVE
YOU A 3 PAGE DISSERTATION ON WHY THEY WERE
WRONG BUT THEY WEREN'T REALLY WRONG THEY WERE
RIGHT JUST NOT THE KIND OF RIGHT YOU EXPECTED.
Lady MacDuff, 11-14—probably referring to bureaucrats
AS WEATHER FANATICS WE ALL KNOW THAT THERE ARE
GOING TO BE HITS & MISSES. THIS IS A FIELD WHERE 1-2
DEGREES, 1-2 MILES, 1-2 MILLIBARS, CAN MAKE A
WORLD OF DIFFERENCE
IT IS QUITE SURPRISING TO FIND OUT HOW MANY
BATTLES AND OTHER HISTORICAL EVENTS WERE WON, OR
OTHERWISE DETERMINED, BY THE MOST DAUNTING,
UNCONTROLLABLE FORCE - WEATHER. LOTS OF
EXAMPLES IN BOTH THE CIVIL WAR AND THE
REVOLUTIONARY WAR. ACTUALLY HISTORY IS SHOT
THROUGH WITH SUCH EXAMPLES
I WOULD SWAP A PALM TREE FOR A PINE TREE ANY DAY
Al Cvervik, 12-7
. WELL USUALLY WE ARE THE ONES WITH 36 DEGREES AND
RAIN WHILE THE WHITE IS ALL UP NORTH
RATINGS AND HYPE FOR THE ALMIGHTY DOLLAR: THAT’S
THE MOTIVATION, NOT SCIENCE OR TRUTH.
Planet Master, 12-19
INLAND VS COAST. ELEVATION VS LOWLAND. NORTH VS
SOUTH. I LIVE IN A BASTARDIZED AREA THAT DOESN'T
FIT ANYWHERE HERE IN SW VA. I HAVE FOUND THAT MY
WEATHER WILL CLOSELY FOLLOW MID ATLANTIC
WEATHER A LOT OF TIMES BUT IT'S FAR FROM A
PERFECT MATCH. I DON'T REALLY CARE WHAT MY
LOCAL WEATHER DOES, NOT LIKE SOME DO. I DO FIND BIG
OR EXTREME WEATHER INTERESTING, INCLUDING BIG
SNOWSTORMS. AND OBVIOUSLY BEING STUCK AT HOME
WATCHING A FOOT PLUS SNOWSTORM FALL IS ITS OWN
RELAXING PEACEFUL EXPERIENCE FOR I WOULD THINK
JUST ABOUT ANYONE.
The August of 2018 arrived in the Northeast in a blur, and it was sure a painful one. This month was dominated by the Bermuda High, propelling high dewpoint temperatures into the entirety of the Northeast and Mid-Atlantic regions.
@StretchCT was the first to open a thread on the pattern (it remains on the blighted AccuWeather Forums at the time of this writing, but will soon be deleted). A heat wave ensued, cooking the region in high temperatures, but it was only the beginning of a disruptively hot and humid summer.
August opened with a small thunderstorm event. The first to be documented on this forum was a notable light-show producer, while at the same time not causing too much damage. It provided beautiful pictures, while at the same time not being a "bad storm."
The second thread for the MidAtl/NE in the new forums was destined to be about the ensuing upper level low system that was impacting the region, bringing with it a variety of flooding concerns. This was forecasted using the Typhoon Rule, and boy did it deliver. Meanwhile, areas to the north of the storm continued to bake, with temperatures in the mid-80s in Montreal and Burlington. Under the ULL, overcast skies dominated the weather for multiple days.
It was followed by yet another small severe storm event. Again, not much to note here, but the rain tally was slowly starting to add up.
Another summer rainstorm marched in a few days later. With a saturated ground and a large system, flooding was bound to happen. New Jersey was right in the crosshairs. High PWATs made efficient rain producers, once again adding to the rain total.
A brief respite was needed, and arrived. A brief period of refreshing air, with low dewpoint temperatures, entered the region. The northern tier experienced wildfire smoke, arriving all the way from Canada, but their hazy mornings were only a slight blip in the marked reduction in overall comfort and happiness. Alas, this was extremely short-lived, with the sticky humidity returning slightly earlier than expected
A series of heat waves began to test the patience of many throughout the forum. The heat was not headline-worthy due to its lack of high air temperatures, but the humidity made the difference. In fact, August had already been a record in average dewpoint temperatures for some, and the Bermuda High was just getting settled in. The heat returned on August 26th with a vengeance. Days of 80+ dewpoint temperatures made air conditioning borderline essential, and plagued the outdoor work schedules of many. Small, pop-up severe storms were commonplace in the unstable environment.
The temporarily-absent rains returned in CTP in a surprise move. Flash Flood Warnings were issued to close August, with numerous highways being closed, cars being abandoned, and water rescues being performed. Locally, almost double-digit rainfall numbers were recorded, once again adding to an already wet month.
September carried on where August had left off. Heat waves continued with seemingly relentless dewpoint temperatures assaulting the patience of many.
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Everyone in my area has been complaining about how it just goes directly from summer to winter, and then from winter to summer. It does seem like Fall and Spring are becoming less relevant, but is there proof of this? How do we go about trying to prove this "theory"?
I'll start with some basic research - have Octobers been warmer than normal, representing an extension of summer? You can get data from the High Plains Regional Climate Center. I put this in the Long Range thread for starters, but the results for the NE/MA show that yes, Octobers have been warming. 9 of the Octobers since 2003 have been warmer than normal, 2 seasonal and 5 colder. But since 2010, only one was cooler and one seasonal. Here is a gif of the NE Octobers. Complicating things is that the scale changes each year and typically the entire region doesn't have the same result, so I'm just eyeballing it.
What about the rest of the CONUS? At least the scale is the same year over year.
What about the winter into spring? Let's look at April. In the NE (you can spot your state and count for your own result) , there was a better mix - 8 were higher, 6 colder and 2 seasonal. However, the warm years took place prior to 2012 (except for 2017) and the cooler years took place post 2012.
So, the maps kinda sorta, unscientifically validate the feeling that winters and summers are lasting longer, at the expense of spring and fall, at least in the NE.
Any thoughts on why? Where to start? ENSO? PDO? QBO? EPO? AO? Sunspots? Or is it just that we are seeing warmer temperatures in general?
Forecasting / General Post
Winter's Opening Salvo
November 15 2018 - 0200z
I have my work schedule arranged in such a way that I enjoy a few consecutive days off in the middle of the week. It gives me a chance to "catch up", physically and emotionally, as well as providing a block of time to work on writing and other such projects. There is a pizza place that I frequent on these off days; frequent a little too much, if my rough calculations about yearly spending there are anything to go by. What can I say; they make really good pizza. I left around 15z today to get lunch, and noticed that we finally seem to have turned the corner from one season to the other. There is a solid chill in the air, stemming from a cold air mass originating deep in arctic Canada, and a classic winter wind that I can still hear from time to time as I write this. Perhaps nothing signifies our concluding transition, however, as much as the start of the first significant region-wide wintry event drawing to less than a day away.
This is a true "mixed bag" event, that is, one that will, somewhere, drop every type of wintry precipitation. Many storms have unresolved uncertainties even within the H+24 to H+36 range; the classic question in so many winter nor'easters is the exact location and orientation of the "deformation band", which often yields the highest local snow totals of the storm. For this event, however, the most critical remaining uncertainties, in my opinion, pertain to local temperature profiles, rather than QPF maxima and minima. To explain, allow me to first break down how these temperature profiles relate to precipitation type ("p-type"), and how local microclimates can have major effects on said p-types. I will then provide a brief summary of my forecast thoughts for the storm, and conclude with a safety tip or two. Shall we begin?
The most effective way for meteorologists to look at atmospheric conditions as a function of altitude are through the use of atmospheric soundings. These are launched by the National Weather Service several times a day, with exact frequency depending on regional and/or special requirements (for example, special soundings may be launched prior to a severe weather event, or to gain data for model input in high-consequence situations such as an impending hurricane landfall). Soundings usually consist of a radiosonde delivered via a weather balloon; rockets are the most common alternative. NWS sounding data can be obtained on the Storm Prediction Center website, the NCAR, or from local NWS Weather Forecast Office pages. A typical sounding (in this case, the 12z or 7am sounding from Albany, NY) may look something like this:
This is a LOT of data. The bottom boxes, as well as the hodograph (wind strength and direction relative to altitude) and surrounding charts are most important for protection of severe weather, and as such, will be disregarded for this post. What I want to focus on here, out of all that, is the red line on the plot seen on the top left of the data display. The chart itself is called a Skew-T Log-P diagram; that is, the temperature lines are skewed at an angle, and the pressure lines are represented in logarithmic format. For more reading, you can access some helpful information here, here, and here. That line is a visual representation of the air temperature at different altitudes; the former measured in °C, and the latter in hPa/mb (a note of conversion: 1 hectopascal, or hPa, is equivalent to 1 millibar, or mb). Let's take a closer look, shall we?
Remember that the Skew in Skew-T Log-P denotes the "skewing" of temperature lines off to an angle. The pair of straight blue dotted lines above highlight 10°C and 0°C from left to right. The green line, for reference, measures the dewpoint. Altitude, as I mentioned above, is measured in terms of atmospheric pressure; 1000hPa roughly equates to the surface (in low-lying areas; in higher elevations, the "surface" pressure may be significantly lower). 850hPa is about 5,000 feet, and 700hPa is approximately 10,000 feet. In terms of the temperature profiles I am about to discuss, we are going to focus on the 700hPa-1000hPa range, which is the most important in determining p-types for a specific location. One should note that the exact "true" altitude of a certain hPa line changes in response to temperature; the higher the temperature, the higher the altitude, as illustrated in this graphic.
So, I promised a discussion about temperature profiles. Specifically, how different profiles affect p-types, and how microclimates factor into that affectation. Nearly all precipitation occurring during the colder months of the year starts out as snow, high above the earth where it forms. How it lands on the ground, however, is a factor of two different temperatures: air and ground. We will start with the former. Imagine a single snowflake falling through the atmosphere. As it descends, the temperature of each layer of air it passes through will determine the end p-type of the molecule. If the entire air column is below freezing, the snowflake will stay a snowflake; likewise, if the entire column is above freezing, the snowflake will melt and land as plain rain. Where things get a bit complicated are when there is a "warm nose" somewhere in the lower to mid atmosphere (commonly between 700 and 900 hPa). When this happens, the snowflake will melt and refreeze. If the warm air intrusion is relatively shallow, with a deeper layer of cold below, the molecule will fall as sleet. If the warm layer is deeper, with less cold air available near the surface, the molecule will fall as freezing rain. The chart below is a visual representation of these different temperature profiles.
Tropical Tidbits and Pivotal WX both have point-and-click forecast soundings for several models; you can also plug in an airport identifier (such as KJFK) in the viewer window to pull up a forecast sounding for that location. I encourage all of you to play around with these viewers. Compare them for your location from model to model, and draw your own conclusions.
In regards to rain versus freezing rain, ground temperature also comes into play. Rain falling onto a -5°C surface will freeze; rain falling onto a 5°C surface will not. In that regard, even if most of the layer is above freezing, a cold surface level with subfreezing ground temperatures can lead to "ice on contact". Microclimates come into play here; small, yet crucial, variations in local temperatures coinciding with elevation, local wind flow, bodies of water, etc. Different types of soil will warm and cool at different rates. The water table plays into these things. These minute variations in ground and surface air temperatures can lead to different p-types falling over very small distances. Such factors are important to consider when forecasting a storm like this, where the temperature profile is proved to be variable during the course of the storm, and outcomes may be influenced by rather small changes in temperature. Typically, each microclimate is best understood by those who live nearby. Think to yourselves; what is that one place in town that always gets an extra inch of snow?
Now, I said I'd make some predictions, and I suppose I should live up to that. Below are the forecast snow accumulation maps from the 18z 12km NAM, 3km NAM, RDPS (Canadian short range mesoscale model), and the 00z HRRR (through 8z Friday, some areas will see more after that time). These show ratios of 10:1 (that is, 10" of snow for every 1" of QPF), and exclude sleet and freezing rain.
Now, here are my thoughts (north of the black dashed line has the best chance to stay all snow):
What, you wanted more? I will leave brief word on safety to conclude this message. Drive carefully, especially in areas with microclimate variations. Rain can turn to freezing rain when you drive up a hill, and road conditions can meteorite very quickly. Plan for extra travel time. Power outages may be more of a threat than with many comparable storms due to the saturated nature of the ground. Might not take much on a tree to knock it over.
Thank you for reading. Pass it on if you wish.
#1, 2 - Storm Prediction Center
#3 - National Weather Service
#4 - Wikipedia
#5, 6, 7, 8, - Pivotal Weather
#9 - Base Map from Free World Maps / Google Image Search
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If anyone is familiar with the LJS index they would be keenly looking upon Japan and waiting for snow to fall.
Well it looks to be occurring in or around the 20th.
The LJS index ignores all heights and troughs and ridges and strictly goes on precipitation type on or very near Aomori, Japan (a rough correlate to the 40 degree north US coast).
The LJS also utilizes a short lag correlate of only 6-8 days.
The index was created proprietarily over the years by following the east Asia rule. It’s been observed that when precipitation is forecasted as snow over Aomori that often times the US correlate also would be forecasted snow.
The proprietary calculations allow the index to not only predict a date of snowfall but also adjust accordingly for possible heavier snow and increasingly hazardous conditions.
Generally an index of +3.0 or higher means that snowfall can be expected over eastern PA and nearby regions.
An index of +6.0 or higher means that possible snowfall over a good portion of PA and NJ is possible.
Ultimately an index of +10.0 or higher means a multi-region wide multi day storm is possible. This rating is only reserved for the most detrimental snowstorms in central Japan.
I will be calculating the LJS index this year approximately 8-10days in advance of a correlative snowfall date.
Currently modeling shows the first + index rating for the US occurring around the 26-28th of November.
However, modeling in east Asia is extremely volatile so index calculations are usually never made until 2 days prior to a Japanese snowfall. Therefore even though modeling shows snow in Japan on a certain date the index will not be tripped until JMA forecasts are issued. Only at that time can the LJS index be truly calculated.
Cheers, take care and do stay tuned fir LJS index updates!
Noticing that the Blob is re-appearing. This patch of warm water in the Gulf of Alaska was predominant in the winter of 13-14 which was a cold and snowy one for the NE.
Also noticing on the gif of the daily anomalies for the last week, it may be dissipating. ERSL SST's
Others have noticed its return as well.
Should note that the ENSO signal for 13-14 was a weak La Nina to neutral, so not comparable to this year's weak Nino. 13-14 was cold in the East and I had 58" of snow
2013 -0.4 -0.3 -0.2 -0.2 -0.3 -0.3 -0.4 -0.4 -0.3 -0.2 -0.2 -0.3 2014 -0.4 -0.4 -0.2 0.1 0.3 0.2 0.1 0.0 0.2 0.4 0.6 0.7
Now before you get excited seeing the El nino conditions appearing in 2014, the blob had already spread out along the PAC coast by then. 2014 was also cold in the East and I again got 58" of snow. Note, my guesstimate for snow in my backyard for this year is 45-55" and leaning toward the 50-55" range.
So I'm not really sure how much affect the blob has. It forms due to already existing atmospheric conditions and per linked sources, doesn't control the atmosphere, rather at that latitude, the atmosphere controls it. If the blob moves in the way it did in 2014-15, then combined with a weak nino, I could end up flipping to a colder forecast.
These are the final standings for most quotes making my weekly top 100. The first quote from the forums made my top 100 in January 2009, and the most recent quote made it in July of this year. Several quotes from the old forums are still on my top 100. Here is everybody who made my top 100 at least five times. A few people had fewer than five charted quotes but still made the top 10 once or twice. The person with the most charted quotes, surprisingly, never made the top 10. A few people have added to their totals since WXDisco opened. I will have an updated version of this list in a couple of months.
MAINE JAY 12
MDBLUE RIDGE 6
MILLER A 6
POCONO SNOW 5
Coming soon: Forum Members with Highest-charting Quotes
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Hello. I dont really want to post this on the main boards where 12 million people can see, but I thought I'd still post here so that the 'main people' on the board can get word... While I leave the weather stuff to the experts, I finally have something I can contribute - some footage from a couple of my cameras. I had storm surge up to my doors for Hurricane Hermine a couple years ago (I have an image gallery w/ some pix)... and if TS Michael takes a similar path, it could also make for some interesting camera shots, or worse (lol). I didn't have the cameras back then for Hermine. I definitely cant guarantee the feed will always be up for the entire next week (in fact it will prob go down often as I work and do various things) but I'll try to have it up at least for the interesting parts over the next few days, unless I end up with 12 million people watching, lol.
Happy storm chasing! Here's the feed:
[ Note to the 0.000001% thieves: I have ADT, firepower, neighbors and friends with firepower, and a whole separate NVR of more cameras besides this one which I choose to make public. Also - a 20 pound female schnauzer, lol. :) Also, despite what the twitch stream is, every camera is high resolution 4K with infra-red night vision. ]
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On September 1, 1862 the Batlle of Ox Hill at Chantilly was fought during severe thunderstorms. It was one of the only battles of the Civil War known to be fought under stormy weather conditions. While our military troops currently view adverse weather and low visiblity environments to be advantageous, this was not the case for troops in the Civil War era. Military tactics at this time favored engagements between large numbers of troops, and so stealth was not usually a primary concern. Combat during the Civil War was always brutal beyond belief, but the weather conditions at this engagement led to even more confusion and difficult fighting conditions than usual.
Prior to the Battle of Chantilly, Union troops had been defeated at the second Battle of Manassas. Exhausted and battle weary, they were retreating toward Washington to regroup. The Confederate troops attempted to flank their movement and cut off their retreat. A small skirmish alerted the Union commanders to the Confederate movements and they responded by attacking the Confederate troops. This caught the Southern troops by surprise at Ox Hill. The Union army attempted to exploit the advantage of surprise by pressing the attack as the Confederate troops dug in at Ox Hill. Meanwhile, a very strong cold front was passing through the area, which led to the severe storms which were a decisive factor in the outcome of this battle. While technically a Confederate victory, the Southern troops did not accomplish their goals in this battle or its aftermath.
The weather on this day was notable due to an extremely strong early season cold front – the exact kind of cold front many are wishful for this year but we currently can find no sign of on the horizon. It was clearly strong and Canadian in origin, and being only September 1, was pushing into hot and humid summer conditions. This is a recipe for severe thunderstorms, and that matches perfectly with the accounts from the Battle of Ox Hill. Prior to the passage of the cold front, winds were observed out of the south. After the passage of the front, the winds had shifted to the northwest and became quite gusty. The storms produced very heavy rain, strong winds from the downbursts, and frequent cloud to ground lightning. Some of these storms passed directly over the battlefield.
These Civil War troops were battle hardened veterans. They were accustomed to the intense fighting conditions of Civil War battlefields, including close proximity to rifle and cannon fire as well as hand to hand combat. Dealing with those conditions while also enduring severe thunderstorms was a challenge to even the most experienced of these men. A firsthand account from one Private Greely in the Union army is indicative of this: ”The roll of musketry and the roar of cannon left all of us unmoved, but the crash of thunder and the vividness of the lightning, whose blinding flashes seemed to be in our very midst, caused the uneasiness and disturbance among some of the bravest men.”
Early on in the battle, General Isaac Stevens of the Union army was killed as the storms were just getting underway. Having seen his son felled by enemy fire, he led the Union charge while holding the battle flag. This made him an obvious target for the enemy and he was subsequently shot and killed. He was not the only Union general to die by enemy fire on this day. Union General Philip Kearny led the Northern reinforcements that arrived on the battlefield later that afternoon. Arriving during the height of a thunderstorm, he became disoriented by the limited visibility and rode directly into the Confederate lines. Once he realized his error, he turned and tried to ride away but was shot down before he could retreat to his own lines.
The torrential rainfall caused issues with the rifle ammunition. Unable to keep their powder dry, both sides affixed bayonets and resorted to hand to hand combat. This 19th century battlefield had turned medieval, with a huge group of soldiers fighting with blades and clubs in a brutal fight for survival. Estimated casualty figures from this battle are over 2000. While the Battle of Ox Hill is not one of the more famous Civil War engagements, there was a lot at stake here; the outcome was dictated in large part by the weather conditions. After hours of fighting in terrible conditions, the battle slowly came to an end as the sun went down. The men on both sides were very tired and very cold. They had been fighting tooth and nail for hours in the lightning, thunder, and windblown rain. The cold front had now passed and temperatures dropped to fall like conditions.
The results of this battle appeared to favor the South at first glance. The Union had lost two of its most respected and popular generals. The Union troops were the ones who retreated from the battlefield with the setting of the sun on this day, leaving the Confederates in possession of Ox Hill. Upon closer examination, the outcome was not what General Lee had in mind. The Union troops were not stopped from retreating and the defeat was not as crushing as what was originally envisioned. General Lee’s orignal plan was to incapacitate this group, and then turn his attention toward an attack towards Washington. Going in to the battle, the Confederates had superior numbers and a tactical advantage. But when the North was able to begin the battle preemptively, they were able to gain an advantage due to the element of surprise. Added to this, the confusion and chaos caused by the thunderstorms prevented the Confederate army from carrying out its battle plan effectively. In the end, the Northern troops were able to escape and the Southern troops were unable to launch an attack on Washington. The thunderstorms on September 1, 1862 played a huge role in the war, even though this particular battle is not usually listed among the more significant battles of the Civil War.
And we sure hope it has no notion of (ever) leaving (though we know that nothing is forever).
The old pattern is dead (for now) and may it remain in the dust bin of history (for at least a while). Let's let NWS speak to just how.
Great news for local hot spots that rely on less than soaked conditions (e.g. - golf course, ice cream vendors, local fundraiser fairs).
I'm going to keep this entry short - not even look into the next pattern change (not that it will be bad) just so we can focus on simply enjoying the next 5-7 days of sunny Summer delight. 🙂
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Plenty of harmony in the pattern analysis over the past month. Interesting to note the uptick in correlation between RRWT projected and observed 500mb hPa anomaly. Attached is the 46-50d outlook verification from 6/29 for 8/14-18. More verification maps here; http://www.consonantchaos.com/a-all.html
If there are any questions, comments, or suggestions on the material presented please let me know. Thank you for reading.
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The Dog Days of Summer are here!
Since the end of July we have been in the soup here on Long Island. Very muggy, tropical haze and down right hot to boot. Not often see 90 here at the shore but this August has made that a daily thing.
While those just inland have gotten torrential rains and cooling thunderstorms at the expense of flooding we have gotten very little. I have been going full steam with the sprinklers for the past two weeks just to keep the brown lawn!
Pattern looks to continue for at least the remainder of this week. Keeping cool thinking of those valley snows!
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