Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/20/20

Area Forecast Discussion
National Weather Service Amarillo TX
522 PM CST Wed Feb 19 2020 .AVIATION... 00Z TAF Cycle VFR conditions expected at the Amarillo TAF site until around 08Z Thursday and then MVFR to IFR conditions through around 18Z Thursday. VFR conditions expected to return to the Amarillo TAF site after 18Z to 20Z Thursday. Snow is expected at the Amarillo TAF site between about 06Z Thursday and 15Z Thursday. Winds will be southeast to east 5 to 15 knots and then becoming north to northeast 10 to 20 knots after 08Z Thursday. VFR conditions expected at the Dalhart TAF site until around 06Z Thursday and then becoming MVFR to IFR after 06Z with VFR conditions expected to return after 21Z Thursday. Snow is expected at the Dalhart TAF site between about 06Z and 15Z Thursday. Southeast to east winds 5 to 15 knots becoming north to northeast 10 to 20 knots after 06Z Thursday. VFR conditions expected at the Guymon TAF site until around 06Z Thursday and then becoming MVFR to IFR between about 06Z and 20Z Thursday. VFR conditions are expected to return after 20Z to 23Z Thursday. Snow expected at the Guymon TAF site after 06Z until around 12Z Thursday. Southeast to east winds 5 to 15 knots and then becoming north to northeast 10 to 20 knots after 06Z Thursday. The north to northeast winds will diminish to around 5 to 15 knots after 20Z Thursday. Schneider && .PREV DISCUSSION... /Issued 402 PM CST Wed Feb 19 2020/ SHORT TERM...Today through Tomorrow... Current RAP analysis shows the midlevel shortwave disturbance digging across northern California. Models show this positively tilted weak wave crossing Nevada and Utah this afternoon and tonight before continuing eastward across and out of the plains by tomorrow evening. Weak disturbances advected ahead of the wave, along with PVA will assist in getting the winter precipitation started in the Oklahoma Panhandle. An associated cold front will dive south through the Oklahoma Panhandle around 00z and be through the Texas Panhandle by 06z. Weak frontogenesis will provide additional ascent for a few hours, mainly in the north northwest portions of the Panhandles as the cold air filters into the area. Towards the 06z to 12z time period, the exit region of a jet streak will set up over the Panhandles with additional dynamics from the ageostrophic component. This may result in higher snowfall rates for this period of time. Dynamics are important, but so is the moisture source. A surge of midlevel moisture from the Pacific will fill in the area, but as the wave moves east the moisture shifts south, dry air overtakes the midlevels. NAM soundings from 06z to 12z show where moisture will fill in the column from the surface to 500-600mb. The lower levels will continue to remain saturated for slightly longer, leading way for lingering dendrites to reach the surface after 12z. The moisture will eventually subside in the mid-morning hours from north to south. With cloud cover all day today and continuing through the night, surface temperatures will likely take longer to cool until precipitation begins. With temperatures potentially above freezing at the surface, there is a chance to see rain/freezing rain before transitioning to snow. Once precipitation begins and temperatures begin to wet bulb, below freezing temperatures will quickly arrive and remain through the night and into tomorrow morning as colder air filters in behind the front. Onset of precipitation will be as early as 00z to 03z tonight in the western Oklahoma Panhandle and northwestern Texas Panhandle. After 06z, the chance for precipitation will remain in the northwest and begin to linger south. Approaching the morning hours, precipitation will begin to diminish from north to south with all precipitation ending by 18z. The northwest Panhandles will see snow amounts of 1 to 3 inches with the remaining Panhandles having the potential to see zero to an inch of snow. Locally higher amounts are possible, especially in the northwest where temperatures have the chance to wet bulb faster and precipitate earlier, along with marginally better dynamic forcing. Behind the front winds will be 10 to 20 mph with the potential to see some blowing snow tomorrow morning. Cloud cover will remain through the early evening hours tomorrow before starting to clear, with high temperatures to remain in the 30s. However, in the far southeast where little precipitation is expected, temperatures may rise into the lower 40s. Rutt LONG TERM...Thursday night through Wednesday. Benign weather is expected Thursday night through Friday night as the forecast area awaits the next upper level storm system. This particular upper level low pressure system is progged to move from southern CA on Saturday morning eastward to the four corners region and across the southern high plains by late Sunday afternoon. Pops return to the OK and TX Panhandles Saturday into Sunday. The atmospheric temperature profile associated with this next storm system will be on the warm side. Therefore, precipitation should remain all liquid Saturday into Sunday. Dry weather returns for Sunday night through Monday night. Another, colder upper level trof is then forecast to affect the region around next Tuesday, with the corresponding cold front expected to move across the area Monday afternoon and evening. This far out in time, have utilized a blend of model pops for next Tuesday, which is basically in the slight chance category. 02 && .AMA Watches/Warnings/Advisories... TX...Winter Weather Advisory until 9 AM CST Thursday for the following zones: Dallam...Hartley...Sherman. OK...Winter Weather Advisory until 9 AM CST Thursday for the following zones: Beaver...Cimarron...Texas. && $$ 11
Area Forecast Discussion
National Weather Service Boston/Norton MA
959 PM EST Wed Feb 19 2020 .SYNOPSIS... Winds continue to diminish overnight, but much colder weather works into the region tonight and Thursday. Below-normal temperatures continue into Friday, before temperatures return to above normal levels for the weekend. Above normal temperatures continue into early next week with the next chance of precipitation on Monday and Tuesday. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... 10 PM Update... Previous forecast is on track as winds continue to diminish as large high pressure slowly builds in from the west. Skies were clear, but should see some clouds work into at least western MA/northern CT toward daybreak. This is result of some remnant Lake moisture, but it will remain dry. Cold advection will continue allowing low temps mainly in the middle teens to lower 20s by daybreak. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... Thursday... Mid level trough axis approaches from the Gt Lakes with an area of mid/high level moisture moving through ahead of it, especially near the coast. In addition, cross sections show considerable low level moisture developing. Result will be more cloud cover but should see partial sunshine. Highs will range from the upper 20s to mid 30s but winds with considerably less wind than today. Thursday night... Trough axis moves through with high pres building into New Eng. Expect clearing skies and light winds which will result in a cold night. Lows will drop into the single numbers in many locations, except teens closer to the coast and in the urban centers. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... Highlights... * Below normal temperatures continue on Friday, but begin to rebound Friday night. Temperatures trending upward into early next week. * Dry through much of the long term. Next shot of precipitation is Monday into Tuesday. Looks like mainly rain at this point in time, but it is still too early to determine the specific details. Friday... A trough will be located just offshore of New England early on Friday, while a ridge axis is situated over the Great Lakes region. The ridge will gradually build into New England on Friday while the trough lifts further offshore. Good agreement amongst guidance with the 850 hPa ridge sliding through by the afternoon. This shifts winds aloft from northwesterly cold air advection to a westerly direction, which advects warm air in. This happens a bit too late to impact the high temperatures on Friday. So it still will be colder than normal with temperatures ranging from the 20s across the higher elevations to the low 30s along the coast. Dry and quiet weather continues. Friday night through Sunday Night... The dry and quiet weather persists with good agreement amongst guidance. High pressure shifts from the Southeast US offshore late on Saturday into Sunday. Temperatures will trend upward due to southwesterly warm air advection aloft with 0 to +2 degree Celsius 850 hPa air moving in. High temperatures on Saturday range from the 30s across the higher elevations to the low to mid 40s along the coast. Readings on Sunday range from near 40 across the higher elevations to near 50 degrees along the coast. Monday and Tuesday... Next shot of precipitation is on Monday into Tuesday. High pressure builds well offshore. A cutoff low is progged to lift from the Central Plains late on Sunday northeastward into the Great Lakes Region. A surface low develops somewhere from the Mississippi River Valley to the Southeast US and lifts northeastward. Still some significant timing differences with the GFS/ECMWF being much slower than the latest GEM guidance. Run-to-run differences suggest things trending slower, but being this far out this trend could change. Kept the NBM guidance at this point in time. Looks like mainly rain, but will need to hammer down ptype details once we get closer to the event. Temperatures remain mild with highs on Monday and Tuesday ranging from the 40s to the low 50s. Expect the warmest readings along coastal areas. && .AVIATION /03Z THURSDAY THROUGH MONDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 00Z Discussion... VFR conditions expected through the forecast. A trough swings in from the Great Lakes bringing bringing 4-6 kft ceilings in western MA. This will gradually expand across southern New England through Thursday. Well captured by the latest RAP RH at 850 hPa. Tonight...High confidence on the trends, but moderate confidence on the timing of when gusty winds end. NW winds diminishing overnight. Thinking roughly between 02-06Z per RAP/NAM and GLAMP guidance. Winds remaining NW. Thursday...High confidence. Gusty winds redevelop, but will not be as gusty as today. Should see gusts around 15-20 kts once the mixed layer develops between 13-15Z. Gusts end during the evening once the mixed layer decouples. Roughly between 22-02Z. KBOS Terminal...High confidence in TAF. KBDL Terminal...High confidence in TAF. Outlook /Thursday Night through Monday/... Thursday Night through Saturday: VFR. Breezy. Saturday Night through Sunday Night: VFR. Monday: Mainly VFR, with areas MVFR possible. Chance RA. && .MARINE... Tonight...High confidence. Gradually diminishing wind as gradient relaxes. 25-30 kt gusts this evening, dropping to 15-20 kt by late tonight. Thursday and Thursday night...High confidence. Winds mostly below SCA with NW gusts 15-20 kt Outlook /Thursday Night through Monday/... Thursday Night through Friday Night: Winds less than 25 kt. Seas locally approaching 5 ft. Saturday: Winds less than 25 kt. Areas of seas approaching 5 ft. Saturday Night: Winds less than 25 kt. Seas locally approaching 5 ft. Sunday through Sunday Night: Winds less than 25 kt. Monday: Winds less than 25 kt. Chance of rain. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory until 4 AM EST Thursday for ANZ231>235- 237-251-256. Small Craft Advisory until 1 PM EST Thursday for ANZ250-254. Small Craft Advisory until 7 AM EST Thursday for ANZ255. && $$ SYNOPSIS...KJC/BL NEAR TERM...Frank SHORT TERM...KJC LONG TERM...BL AVIATION...KJC/BL MARINE...KJC/BL
Area Forecast Discussion
National Weather Service State College PA
1052 PM EST Wed Feb 19 2020 .SYNOPSIS... A large area of Canadian high pressure will move southeast to the Lower Mississippi and Tennessee Valleys by early Saturday, dominating our weather with mainly dry and and seasonably cold conditions through Friday. Just a few flurries will fly across the northern tier this afternoon into Thursday morning. A weak mid and upper level disturbance will move east and tap limited low level moisture off the Great Lakes, bringing the chance of snow showers across the Northwest half of the state Thursday with a light coating of snow possible across the Northwest Mountains and Laurel Highlands. The coldest day will be Thursday as high temperatures stay about 10 to 15 degrees below normal. A gradual warming trend will follow for the upcoming weekend with a continuation of dry weather. The next chance for precipitation, mainly in the form of rain, will come Monday into Tuesday. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... Skies will be mainly clear through early tonight, before a deck of thick altocu and altostratus races east from the midwest and spreads across mainly the NW half of the CWA toward daybreak. WNW Wind will diminish this evening to 10 kts or less. Lows tonight will vary from the teens across the Northern Mtns and Laurel Highlands to the low- mid 20s in the SE. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... RAP soundings show a thick shield of mid level clouds covering much of the NW half to two thirds of the state, with cloud bases dipping into the 3.5-5 kft AGL range for a few to several hours during the day Thursday. Stratocu beneath this cloud layer and the lower part of the mid clouds will have temps in the favorable -12 to -18C range for dendritic growth, leading to the chc of flurries from late morning on. The very dry llvl air and scattered-bkn higher cloud bases across the Lower Susq Valley will cause any flakes to vanish before reaching the ground. Expect 925mb temps to drop to the -6 to -12C range for Thurs aftn. Thu/thu night will be the absolute min for temps this week as the ridge of high pressure extends ENE from its center over the Mid Miss Valley. Maxes only around 20F in the northwest and m30s in the SE will be anywhere from 7 to 18F below normals. Skies will become mainly clear Thursday night with temps diving into the single digits across the north, around 10F across the Laurels, and Teens throughout the Central and SE zones. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... High pressure centered over the southeast United States will result in an absolutely gorgeous weekend across the Commonwealth with 3 straight days of blue sky. After a colder-than-average Friday, a warming trend is expected through Sunday as gusty west-southwesterly winds usher in milder temperatures this weekend. As we round out meteorological winter next week, an unsettled pattern returns with a series of weather systems affecting the Commonwealth. The first system arrives Monday evening as rain showers overspread from west to east along a weak cold front. Simultaneously to the cold front`s arrival, a low pressure system tracking east from the Southern Plains will funnel moisture into the northeast during the day on Tuesday. The majority of guidance favors an all-rain solution in Pennsylvania as the 500mb trough preserves neutral tilt and cold air is unable to funnel in. Slightly colder and closer-to- seasonable air settles in for the midweek with gusty winds likely between systems. Though it is beyond the scope of this forecast, storm number 2 arrives late Wednesday into Thursday. Details for this storm are still highly uncertain, but models indicate the potential for a rapidly- deepening system affecting the mid- Atlantic. Additional details will be provided in the coming days. Behind that system, it appears Arctic air may finally settle into the middle-Atlantic. As such, the CPC favors below-normal temperatures in the latest 8-14 day outlook. && .AVIATION /04Z THURSDAY THROUGH MONDAY/... Northwest winds will diminish to under 10 mph this evening with mainly clear skies. Mid level clouds will race in from the west later tonight and persist through Thursday. A period of MVFR is expected at BFD overnight through Thursday midday because of lake induced clouds as winds shift to more northwesterly. Elsewhere, VFR conditions will persist through the forecast period. .Outlook... Fri-Sun...Mainly VFR conditions anticipated as a large area of Canadian high pressure moves southeast to the Central Appalachians by Sat morning. Mon...increasing clouds with a chance of light rain late Monday into Tuesday Central and SE, and rain or wet snow over the NW Mtns. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Lambert NEAR TERM...Lambert SHORT TERM...Lambert LONG TERM...Jurewicz/Banghoff AVIATION...Lambert/Banghoff
Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
817 PM CST Wed Feb 19 2020 .SYNOPSIS... Issued at 304 PM CST Wed Feb 19 2020 H5 analysis from earlier this morning had a closed low over northern portions of Quebec. a trough extended south of this feature into southern Quebec. Another trough of low pressure extended southwest from southwestern Ontario into eastern Idaho, while a ridge of high pressure extended from the Pacific NW coast, north into western portions of the NW Territories of Canada. Across western and north central Nebraska, intense mid level frontogenesis has developed across the Sandhills this morning and has spread snow to the Sandhills and swrn Nebraska. Some of this has had intensities of up to a half to three quarters of an inch per hour across the central Sandhills. As of 2 PM, snow amounts ranged from around 2 inches at North Platte, to 5 inches at Thedford, Halsey, O`Neill and around Arthur. In addition to these reports, a 6 inch report came out of far southwestern Hooker county around 11 am CT this morning. Though we haven`t received an additional report from this location, based on radar returns over the past 2 to 4 hours, wouldn`t be surprised if we see some 8 inch reports along the McPherson/Hooker county line, east to around Dunning. Skies remained cloudy this afternoon with some limited clearing noted along the SD/Nebr. border. Temperatures as of 2 PM CT ranged from 12 at O`Neill to 22 at Imperial. && .UPDATE... Issued at 815 PM CST Wed Feb 19 2020 The accumulating snow has ended across southwest and north central Nebraska. The Winter Weather Advisory has been cancelled. The RAP and HRRR models indicate widespread subzero temperatures by morning with readings around 5 below zero. The RAP model indicates precipitable water falling to less than 0.10 inches which is backed up the 00Z UNR upper air flight which indicates 0.09 inches of water. This will support tremendous radiational cooling across the blanket of fresh snowfall covering parts of wrn and ncntl Nebraska. Before this dry air moves in, areas of southwest Nebraska and the Sandhills will be prone to patchy fog as suggested by the short term model blended visibility product. The forecast has been updated for flurries this evening, subzero temperatures and patchy fog. Wind chill readings near 20 below zero are possible by morning. && .SHORT TERM...(This evening through Thursday night) Issued at 304 PM CST Wed Feb 19 2020 Based on the latest HRRR and NAM12 solns, snowfall is expected to end fairly quickly this evening. By 00z, the best chances for snow will be confined to areas along and south of highway 92. By Midnight, snow is expected to end across all of southwestern Nebraska. Given the degree of snow which has already accumulated, as well as forecast snow for this evening, decided to cancel the winter weather advisory for Deuel, Chase, Perkins, Hayes and Frontier counties. In these areas, little or no snow fell today. With forecast snow accums of less than an inch in these areas this evening, feel no need for a winter weather advisory in these areas. Overnight, skies will clear overnight as a strong 1045mb high builds into northern Iowa. Fresh snowcover and light winds will make for bitterly cold temperatures tonight. For lows tonight, started with a blend of MET and MAV guidance, then lowered temps across the board a couple of degrees. On Thursday, winds will shift around to the west and southwest as the high builds into southern Iowa and northern Missouri. Even with the westerly winds, temperatures will remain cold thanks to H85 temps of -3 to -8C along with fresh snow cover. Once again, went ahead and undercut guidance for highs Thursday as widespread snow cover is expected. Lows Thursday night will be seasonal in the teens, as southerly winds are expected not to totally de-couple overnight. .LONG TERM...(Friday through Wednesday) Issued at 304 PM CST Wed Feb 19 2020 Benign weather is expected for Friday through Saturday. A warm front will push into the region Friday with H85 temps reaching into the single digits C Friday afternoon. Even warmer air will push into western and southwestern Nebraska Saturday. With H85 temps reaching into the lower teens, we even may see some lower 60s in the southwestern forecast area Saturday afternoon. The tranquil weather pattern will be short lived though. A southern stream trough and closed low will track into the Four Corners Saturday night, emerging onto the plains of eastern Colorado Sunday. As for the track of this system. It has trended north over the past 24 hours. That being said, locations south of the Interstate could see some rainfall or accumulating snow given the current track of the low as depicted in the models. Have introduced some low pops across the southern forecast area. Precipitation types will be problematic with this system, as arctic air remains well north of the system over southern Canada. Based on the current temp forecast, we could see rain during the day and snow in the nighttime hours. A second system will cross the central CONUS during the middle of next week. As was the case yesterday, both the mid range solutions indicate a midweek system, albeit now much weaker, crossing the central Conus next week. Impacts from the system continue to remain up in the air as the intensity of the system and synoptic setup are uncertain right now. Will need to monitor this one over the next several days. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 630 PM CST Wed Feb 19 2020 Snow is ending from the north and VFR is taking hold across the region. Some late night fog could develop across the recent snow cover, but confidence is not high and have not included in the TAF at this time. Winds overnight will be light. VFR is expected to prevail Thursday. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...CDC SYNOPSIS...Buttler SHORT TERM...Buttler LONG TERM...Buttler AVIATION...Taylor