Gale - An extratropical low or an area of sustained surface winds of 34 (39 mph) to 47 knots (54 mph)
Gap - break in a mountain chain. eg - Cumberland Gap which is suspected to aid in transferring LP to the coast.
GDPS - global deterministic prediction system or GEM
GEM - Global Environmental Multiscale Model operated by the Canadian Meteorological Centre. AKA CMC, Drunk Uncle, GDPS. Runs 2x per day out to 10 days
GEPS - GEM ensemble with 20 members, runs 2x day out to 16 days
GEFS - GFS Ensemble
GFS - Global Forecast System - American operational forecast model runs 4x day out to 15 days. Commonly known as the Goofus and being replaced by the FV3 in 2019. Its 0z run begins to display around 10pm EST or 11pm EDT. The 12z run is around 11 EST and noon EDT.
GLC - Great Lakes Cutter. Storm that heads through the Great Lakes, most hated storm by the MA and NE as it soaks the EC and brings up warm air in the winter.
GMT - Greenwich Mean Time. Also known as Zulu time (z), or Universal Time (UTC). 0z is 8pm EDT or 7pm EST. 12z is 8am EDT or 7am EST.
GOM - Gulf of Mexico
Gravity Wave - sounds really awesome, but its really just a ripple effect. Becomes impressive when caused by convection and is seen on satellite.
Ground Clutter - when your radar image looks messed up, its usually due to ground clutter confusing the radar.
GS - when in context with the EC its Gulf Stream.
GYX - Gray/Portland ME NWS office
H - 1. in context of height H5 is 500mb, H7 700mb, H8 is 850mb. 2. In context of time is same as Hr. as in H48 or Hr72. 3. High as in HP
Hail - ice pellets falling from a thunderstorm, very rare occurrence in the winter, not to be confused with sleet which falls when the lower thermal profile is below freezing.
HECS - Historic East Coast Storm
HLB - High Latitude Blocking - high pressure/ridging in the Arctic or Greenland causes lower pressures/troughing in the mid-latitudes. ..when a weather system matures, it naturally wants to move north and east, but when there's high pressure there, the system can't move north so it can get stuck, blocking the system and causing a prolonged period of cold weather (thanks to ClicheVortex)
HM - Henry Margusity - former Accuweather forecaster known for wearing a "big daddy" hat when a storm is coming.
HP - high pressure
HPN - White Plains, NY airport code
hPa - hectopascal. Unit of pressure equal to 1 mb. Rarely used on this site.
HRRR - High Resolution Rapid Refresh model. Runs hourly out 18 hours with 3k resolution.
HV - Hudson Valley
HWO - Hazardous Weather Outlook - a product of the NWS that alerts the public to hazardous weather. Found on your local NWS page.
IAD - Dulles Airport, VA
IMBY - In my backyard
IR - Infra-red - typically used with a satellite reference
ISP - Islip, LI
ITCZ - Inter-tropical Convergence Zone. The region where the northeasterly and southeasterly tradewinds converge, forming an often continuous band of clouds or thunderstorms near the equator
JB - 1. Joe Bastardi - easily excited and intense met (bodybuilder and wrestler), formerly at Accuweather, now at Weatherbell. 2. Justin Berk - met out of Baltimore, more commonly called Justin rather than JB.
Jet Streak - section of the jet stream which has higher winds. Left Front/Right Rear sections of jet streaks enhance precipitation by encouraging upward motion. For more... click
JMA - Japanese Model, aka the Mayor, 6z and 18z runs are out to 72 hrs. 12z run is out to Hr192
JTWC - Joint Typhoon Warning Center. Naval Meteorological agency which monitors conditions and issues Cyclone warnings for the Indian and Pacific oceans.
Kelvin Waves - eastward propagating equatorial waves which can cause a variation in the thermocline (temperature profile of a water column). For a demo... click
Kts - knots. One kt = 1.15mph
Kuchera ratio - an alternate way to calculate a snow ratio which takes into consideration temperatures at different levels of the atmosphere.
LI - usually Long Island. However can also mean Lifted Index.
LLJ - Lower level jet
LP - low pressure
Longwave (trough) - wave in the atmosphere that is large and usually slower in nature, as marked in green below
LR - typically refers to long range.
LRC - Lezak Recurring Cycle - OFM based on that weather cycles repeat. For more...click
LVL - level
MA - usually means mid-Atlantic. Also means Massachusetts.
Mayor (the) - JMA model
mb - millibar. Typical way we measure air pressure on this site.
MCC - Mesoscale Convective Complex. Large MCS, round or oval, over 100,000 sqkm in area (roughly ohio), with cloud top temps of -32c or less, or 50,000 sqkm if cloud top temps are under -52c.
MCS - Mesoscale Convective System. Cluster of thunderstorms, typically lasting more than 6 hours and peaking at night. Similar to MCC.
MDBR - MD Blue Ridge
MDT - Harrisburg PA airport code .
MECS - Major East Coast Storm
Mesoscale - scale of area affected by weather ranging from 50 miles to a few hundred miles. Synoptic scale includes high pressure and low pressure systems, mesoscale includes smaller storms.
Met - meteorologist
METAR - An international code (Aviation Routine Weather Report) used for reporting, recording and transmitting weather observations.
Miller - an alternative nickname for StretchCT in college.
Miller A - Type of nor'easter that develops in the GOM or SE Coast and rides up coast, as depicted by NWS CTP; also a nickname of a member of this board.
Miller B - a type of nor'easter that crosses the OH or TN Valley and reforms at the coast, riding northeast, as depicted by NWS CTP:
MJ - Maine Jay
MJO - Madden Julian Oscillation. An eastward moving disturbance of clouds, rainfall, winds, and pressure that traverses the planet in the tropics and returns to its initial starting point in 30 to 60 days, on average.
MOS - Model Output Statistics. Short range guidance package sent to 300 stations including precip and temp forecasts.
MRF - Medium range forecast model. Rolled into GFS now.
MSLP - Mean Sea Level Pressure, measured in mb or inches
Mt. Holly - the PHL NWS office
MVY - Martha's Vineyard
NADS - nickle and dime snow
NAM - North America Mesoscale Forecast System - American short range model going out 84 hours, running 4x per day. Only covers North American Domain. Available in 32k resolution, 12k resolution (standard) and 3k resolution. Known for over doing QPS and generally will forecast storms to the west of the GFS.
Nammed - NAM usually puts out the most precip, overdoing it. Shows 4.2" of qpf 48 hrs before the storm, only to have it go to .8" day of, with no track change. So when you have 28" in your back yard on a snow map, you've been nammed.
NAO - North Atlantic Oscillation. The anomalies in sea level pressure between the Icelandic low pressure system and the Azores high pressure system in the North Atlantic Ocean which affects the jet stream. +NAO results in faster flow off the continent and warmer temps along the EC. -NAO results in a more amped jet, deeper longwave troughs and slower moving systems due to blocking. You DO NOT need a -NAO for a EC snow storm. Members swear by it and we can dedicate a whole blog or thread for the topic of the NAO.
NATOR - ukinator. UKMET model.
NAVGEM - Navy Global Environmental Model. Runs 4x day out to 144hr 6z and 18z and 180 hrs for 0z and 12z runs. Tends to be a progressive model as its resolution is less than others.
NAVGEM Rule - most of the time the NAVGEM will be the furthest east with a storm. Thus if you see the NAVGEM move west, others will likely follow. Its not a golden rule per se, but fun to watch as its bias is to be flatter and faster than others.
NCEP - National Centers for Environmental Prediction. Dept of NOAA that is responsible for modeling, winter prediction, ocean prediction and storm prediction.
NE -Northeast or New England
Negative Tilt (negative trough, negatively tilted trough) - trough whose axis runs NW to SE as energy rounds the bottom of the trough. Usually results in storms moving more north than east and is a sign of an intensifying storm.
photo from weather.gov wave patterns
NESIS - Northeast Snowfall Impact Scale, might have been replaced by the RSI, regional snowfall index.
NHC - National Hurricane Center
NOGAPS - old school reference to the NAVGEM, the model run by the US Navy.
NOHRSC - National Operational Hydrologic Remote Sensing Center. Where to go to get current snow analysis.
Nor'Easter - A strong low pressure system that affects the Mid Atlantic and New England States. It can form over land or over the coastal waters. These winter weather events are notorious for producing heavy snow, rain, and tremendous waves that crash onto Atlantic beaches, often causing beach erosion and structural damage. Wind gusts associated with these storms can exceed hurricane force in intensity. A nor'easter gets its name from the continuously strong northeasterly winds blowing in from the ocean ahead of the storm and over the coastal areas.
Nowcast - what members start saying when its getting close to the start of the storm. "Stop looking at models, its time to nowcast". I drink every time I read one of those posts and I'm at home.
Norton - the Boston NWS office (fka Taunton)
NWS - National Weather Service
OBX - Outer Banks, NC
Omega - a term used to describe vertical motion in the atmosphere. High values of Omega relate to strong Upward Vertical Velocity (UVV). If you have high Omega and a saturated atmosphere in the DGZ, you get a snow dump.
ORH - Worcester MA Airport code.
Orographic Lifting - as winds push up against a mountain, the air rises and cools, causing condensation and precipitation.
OTS - out to sea
OV - Ohio Valley