Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/04/19

See below for an aviation forecast discussion for the 00Z TAFs.

&& .SHORT TERM...(This Evening through Monday) Issued at 156 PM CST Sun Feb 3 2019 Really not much change to the progression of this system. We can pick out some dual pol signatures on the west edge of Edmunds county, probably sleet as the lowest scan only lowers to 3kft, which is still above the top of our very cold near surface layer. Expect this progression to continue through the day. CAMS are fairly hit and miss with pockets of snow with this system, and it still looks like some localized mid level frontogenetic forcing will enhance snow at times, but then again, not much help at identifying an exact location. Winds continue to top out around 20G30kt, and while our old snow is not especially blowable, new snow on top of it will probably result in reduced visibility/hazardous travel, so will leave headlines in place. The slow west to east transition for dry conditions is expected this evening/overnight, but winds stay up for most of Monday. Given cold advection and winds, windchill headlines will also remain in place. No other changes in the forecast of note. .LONG TERM...(Monday Night through Sunday) Issued at 156 PM CST Sun Feb 3 2019 High pressure will be over the area at the beginning of the period, then gets pushed east Monday night as low pressure begins to track across the Rockies. May see some light snow showers late Monday night into Tuesday as some weak shortwave energy moves through, but accumulations will be minimal. High pressure briefly noses back in over the area Tuesday night into Wednesday morning, then will see the potential for more widespread snow Wednesday afternoon through Thursday morning as low pressure tracks from Colorado across Kansas to the southern Great Lakes region. At this time, it looks like accumulations will be higher to the south and east of the area, but could see an area of 1 to 3 inches across the southern and eastern parts of the CWA. High pressure then dives back in over the region, keeping conditions dry Thursday night through Saturday night. Some models currently hinting at the potential for more snow toward the end of next weekend. Will stick with chance POPs for Sunday for now. The other main feature of the long term period will be another extended period of cold temperatures. Highs will generally be in the single digits above and below zero Tuesday through Friday, with overnight lows in the single digits and teens below zero Monday night, Tuesday night and Wednesday night, then in the teens to lower 20s below zero Thursday night and Friday night. Expect the potential for some brutally cold wind chills during that time as well. Some slightly warmer air moves in over the weekend, with highs in the single digits and teens above zero Saturday and Sunday. && .AVIATION...(For the 00Z TAFS through 00Z Monday Evening) Issued at 538 PM CST Sun Feb 3 2019 Sub-VFR conditions to continue over the next 6 to 9 hours. Precipitation moving newd across the area, affecting the KMBG (snow) and KPIR (sleet and snow) terminals mainly between now and 03Z, will also move through the KABR (mainly snow) and KATY (sleet and snow) terminals mainly between 01Z and 05Z. Otherwise, blustery northerly winds will create areas of blowing snow overnight, particularly at the KMBG/KABR and KATY terminals. Conditions should be improving by Monday afternoon as winds gradually diminish. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...Winter Weather Advisory until midnight CST /11 PM MST/ tonight for SDZ003>005-009-010. Wind Chill Advisory from midnight CST /11 PM MST/ tonight to noon CST /11 AM MST/ Monday for SDZ003>006-009-010-015>018- 033>037. Winter Weather Advisory until noon CST Monday for SDZ006>008-011. Wind Chill Advisory from 6 AM to 6 PM CST Monday for SDZ007-008- 011-019>023. MN...Winter Weather Advisory until noon CST Monday for MNZ039. Wind Chill Advisory from 6 AM to 6 PM CST Monday for MNZ039-046. && $$ UPDATE...Dorn SHORT TERM...Connelly LONG TERM...Parkin AVIATION...Dorn
Area Forecast Discussion
National Weather Service Bismarck ND
903 PM CST Sun Feb 3 2019 .UPDATE... Issued at 857 PM CST Sun Feb 3 2019 RAP model shows the h700 mb low vicinity of Stanley ND at 9 PM CST. For the rest of the evening will see light snow continue west, and occasional moderate snow north central and east. Will let the warnings and advisories continue for now, but can see a point where we will convert portions of the area to a wind chill advisory for the rest of tonight. This would most likely occur first southwest, possibly as soon as the next update at midnight. Otherwise, current forecast will continue. UPDATE Issued at 601 PM CST Sun Feb 3 2019 Visibilities across the north have been a quarter mile to a half mile in Moderate snow. Visibilities have been coming up a bit at Dickinson, and this seems to correspond with the back edge of the short wave trough. Current forecast looks good for now. && .SHORT TERM...(This evening through Monday) Issued at 240 PM CST Sun Feb 3 2019 The ongoing winter storm highlights the short term forecast period. No changes needed for the current winter storm warnings and advisories. We have already received reports of 3-5 inches of snowfall in parts of northwestern and north central North Dakota as of early this afternoon. Currently, cold arctic air continued to push into North Dakota with northerly winds across the state at 15 to 25 mph. Temperatures ranged from 5 to 10 below zero across the northern half of the state, to around zero to 5 above along the South Dakota border. The anticipated snow for this winter storm entered northwestern North Dakota before daybreak, and had spread across northern and southwestern parts of North Dakota by noon, and was spreading into south central areas early this afternoon. Global and high res models were fairly consistent in the timing/evolution of the developing system, and they indicate the snow continuing tonight across the state. Models depict a significant shortwave lifting northeast out of Wyoming. The leading edge of this wave was evident on regional radars of an enhanced area of radar returns from eastern Montana through the western Dakotas. Thus...this afternoon through early tonight (before midnight) should see continued periods of light/moderate/heavy snowfall across western and central North Dakota. It is possible that by/after midnight, the snow may be tapering off in parts of southwestern North Dakota...and perhaps tapering off over most of the southwest half of the state by daybreak Monday. Later shifts will monitor the trends in radar returns and well as future computer model iterations for that determination. Regarding snowfall totals...the predicted snowfall totals from yesterday`s and this early morning`s forecast appear to be consistent with that of the latest global and high res models. Therefore, no changes needed in the current placement of the winter storm warnings and advisories. Highest snowfall totals are expected across the northern half of the state, mainly along and north of Highway 200 to the Canadian border, with widespread 8 to 10 inches. While the strongest pressure rises will remain to our south, strong cold air advection and modest 3-hour pressure rises will likely create areas of blowing and drifting snow overnight across the central and eastern parts of the state, lasting into Monday. Visibility will be greatly reduced, especially out in open country. The combination of snow accumulations up to 6 inches and areas of blowing and drifting snow will create very difficult travel conditions across the east half of the state tonight and early Monday. Wind chill headlines will likely be needed later tonight and Monday as the winter storm warning and advisories expire/end due to the ending of snow and/or blowing snow. .LONG TERM...(Monday night through Sunday) Issued at 240 PM CST Sun Feb 3 2019 A prolonged arctic outbreak highlights the long term period. A large and well-established Hudson Bay Low will remain entrenched across much of Canada and the north central US states through this week. Meanwhile an upper level longwave trough digging south along the western US coast on the southwestern edge/lobe of the large, broad Hudson Bay Low will continue digging along the west coast through Monday, then begin moving east across the Rockies and into the Plains states by Thursday, finally moving east into the Ohio Valley by Friday. This scenario will keep arctic air entrenched over the Northern Plains, while bringing some shots of light snow to our area from the energy moving through the longwave trough as it moves east across North America. Regarding temperatures: Many locations across central and eastern North Dakota may very well go the entire week without seeing temperatures climb above zero and dangerous wind chills will once again fall into advisory/warning criteria through the week. At the moment, Wednesday night through Friday morning looks to be the coldest time frame, where widespread wind chills of 35 to 45 below zero are expected. Regarding light snow chances: Another opportunity for snow remains in the forecast Monday night- Tuesday night, then another shot on Wednesday. Shortwaves bringing the snow will likely bring higher precipitation amounts to the central and southern Plains, but the entrenched arctic air over our area should keep only lighter amounts of snow reaching North Dakota. We could see an inch or two of new snow Tuesday/Tuesday night, with lighter amounts Wednesday/Wednesday night. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 601 PM CST Sun Feb 3 2019 A winter storm will continue to significantly impact aviation operations across west and central North Dakota tonight into Monday morning. Widespread IFR-LIFR conditions in moderate to heavy snow will continue KISN-KMOT-KBIS-KJMS, slowly improving after 03-06z to light snow with IFR conditions persisting. IFR to Occasional MVFR is expected KDIK. Conditions should slowly improve between 12z-18z Monday to MVFR. && .BIS WATCHES/WARNINGS/ADVISORIES... Winter Storm Warning until noon CST /11 AM MST/ Monday for NDZ001>005-009>013-017>023-025-031>037. Winter Weather Advisory until noon CST /11 AM MST/ Monday for NDZ040>048-050-051. && $$ UPDATE...WAA SHORT TERM...JV LONG TERM...JV AVIATION...WAA
Area Forecast Discussion
National Weather Service Huntsville AL
728 PM CST Sun Feb 3 2019 .NEAR TERM...(Tonight) Issued at 728 PM CST Sun Feb 3 2019 RGB imagery indicates that nearly all of the afternoon SC and CU has dissipated. Thus, had to make wholesale changes to the sky grids overnight which were mostly cloudy. The clearing is also allowing for faster radiational cooling than expected, so have lowered hourly and min temps a few degrees, especially in our eastern zones. The HRRR seems to have a good handle on this trend, so followed closely to this guidance. Otherwise, no other changes are foreseen. .SHORT TERM...(Monday through Tuesday) Issued at 243 PM CST Sun Feb 3 2019 The aforementioned boundary will continue to move east into the region from late Monday morning into Monday afternoon. There will be sufficient moisture and lift to generate scattered light showers along and ahead of this feature. Given the modest forcing, would not expect any heavy downpours, however, and QPF amounts will remain light. The greatest coverage will likely be from 18z Monday afternoon through 03z late Monday evening. Thereafter, the best lift will shift east of the region, and this activity will largely taper off. Temperatures were a little tricky on Monday given the breezy southwesterly winds (which should enhance warm air advection). However, with dense cloud cover expected, felt that highs slightly lower than today were probably still reasonable given the cloud cover and stayed close to guidance of low to mid 60s temperatures. Any cloud cover from Monday should generally linger into Monday night and Tuesday as southwesterly flow continues to enhance the moisture profile. We`ll likely see some warming due to a few breaks in the clouds on Tuesday. However, the warm air advection from the even breezier southwesterly flow will play a large role in creating even milder temperatures (and muggier dewpoints) for Tuesday. It may feel downright sticky on Tuesday, with temperatures climbing into the upper 60s to around 70 degrees in the afternoon (to go along with low 60s dewpoints), despite the cloud cover. A second weak shortwave will pass through the region late Monday night into Tuesday morning, bringing more widely scattered light showers. However, some upper- ridging looks to take place by the afternoon, and we`ll likely see a brief lull in precipitation Tuesday afternoon and evening with the frontal boundary stalled to the north and west over the lower Ohio Valley. .LONG TERM...(Tuesday night through Saturday) Issued at 243 PM CST Sun Feb 3 2019 February will feel more like spring in the extended with above normal temperatures and an abundance of moisture. Southerly flow will be in place even before we reach the extended on Wednesday, providing a foundation of moisture and WAA across the region. On Wednesday, a trough will dig into the Four Corners while a ridge builds into the Southeast. Southwesterly flow aloft will send a disturbance into the region, interacting with a stalled front in the OH Valley. The TN Valley will see scattered to numerous showers with isolated thunderstorms, Wednesday into Thursday with the greatest coverage to our north, closer to the front. A few storms could become strong as a low and mid level jet moves in Wednesday night/Thursday, creating breezy conditions and increasing shear. Thursday will be the warmest day of the week with the combo of WAA and height rises, possibly reaching record high temps. Temps will already be abnormally warm on Wednesday with highs around 70 degrees and overnight lows around 60 degrees, but daytime high temps on Thursday could reach the lower 70s! This will be about 20 degrees above seasonable values, as normal high temps are 53-54 degrees this time of year. The record high temp for Thursday is 73 degrees (1999) at HSV and 74 (1921) at MSL. Models are in much better agreement today with the progression of the trough and cold front. The GFS is now trending towards the ECMWF where the trough has freedom to move into the Plains about a day earlier on Thursday and lift NE up into the Great Lakes due to the persistent ridge in place instead of the OH Valley like it was showing yesterday. As the sfc low heads up into the Great Lakes, the associated cold front will slide SE into the region. Timing is more in line with reaching the TN Valley around Midnight Thursday night, brining another round of numerous to scattered showers. The majority of the rainfall will end Friday morning as the front quickly exits the CWA. A few showers may linger behind the front, but dry conditions will return by Friday night. Temps will be more seasonable behind the front with highs around 50 degrees Friday and Saturday and lows in the 30s. Will see just how much CAA we get with the sfc high centered over the Great Lakes. Regardless, temps will be a bit cooler heading into the weekend. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 510 PM CST Sun Feb 3 2019 VFR flight weather conditions are expected through this evening before ceilings of 015-020agl (MVFR) develop. MVFR ceilings will lift into the 015-025agl range by 16-18Z on Monday with isolated -SHRA possible. The -SHRA will become scattered after 18z with south flow of 8-10kt. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...NONE. TN...NONE. && $$ NEAR TERM...17 SHORT TERM...AMP.24 LONG TERM...JMS AVIATION...17 For more information please visit our website at
Area Forecast Discussion
National Weather Service Key West FL
1001 PM EST Sun Feb 3 2019 .CURRENTLY... In the midst of otherwise quiet weather, GOES-16 fog imagery has been showing the southward advancement of fog along the Southwest Florida coast into KEY`s far northern Gulf waters west of the Ten Thousand Islands. Holes appear to be developing along the leading edge as it spreads south. Otherwise, light north winds have developed as a diffuse surface high pressure ridge builds down from Georgia across the far eastern Gulf. .DISCUSSION...Watching the southward movement of sea fog across the southeast Gulf. Expect the fog to either break up or lift into a low stratus by the time it reaches the Lower and Middle Keys after midnight. Any lingering low stratus on Monday morning should lift and break up easily with the addition of heating from the morning sun. For more details over water, see the marine section. Otherwise the weather over the Florida Keys through Thursday will be fair, benign, and rain-free. A surface ridge is currently building from Georgia down into the far eastern Gulf. This will morph into a surface high center over north and central Florida on Monday afternoon, with this fair-weather feature continuing in place through Tuesday evening. During this time, winds will be particularly light out of the north and northeast. Light northerly surface flow will provide a trickle of drier air, with dewpoints falling unremarkably into the mid 60s on Monday afternoon. Surface high pressure on Wednesday will elongate into a surface ridge that will extend from northeast Florida northeastward into the Atlantic. A turn to easterly breezes and increase in speeds will occur early Wednesday. However, a strong upper ridge will quickly expand from the southwest Gulf across the Florida Peninsula on Wed. It will remain in place through Friday, with the strong upper ridge then sinking south directly over the Keys next Saturday and Sunday. The strong suppressing effect of warm air aloft and large-scale subsidence will nearly eliminate shower chances over the Keys. Temperatures from Thursday through next weekend will run above normal, with highs near 80F and lows in the lower 70s. && .MARINE... The 01z HRRR model shows fog continuing to spread south across the deep waters of the southeast Gulf late this evening and overnight, but satellite imagery already shows significant scattering of the fog as it passes south of T Tower. The 01z HRRR shows fog holding together all the way south to the Marquesas Keys after midnight, but satellite trends do not favor it getting much further south than the latitude of Cape Sable. Regardless of how far south the fog reaches, it should dissipate early Monday morning. Otherwise, a surface ridge is currently building from Georgia down into the far eastern Gulf. This will morph into a surface high center over north and central Florida on Monday afternoon, with this feature continuing in place through Tuesday evening. Mainly light and gentle N-NE breezes are expected on Monday, with some moderate NE breezes over the Straits on Tuesday. Surface high pressure on Wednesday will elongate into a surface ridge that will extend from northeast Florida northeastward into the Atlantic. This will bring freshening east breezes on Wednesday, with moderate to fresh easterlies on Thursday. && .AVIATION... At 955 pm, GOES-16 fog imagery showed that sea fog along the Southwest Florida coast had advanced southward to 45-50 miles north of EYW. At Naples, our closest airport to the north, the latest ob is 3/4SM BR VV002. The southern edge of the fog appears to be breaking up as it moves southward toward the Lower and Middle Keys. Given slightly warmer water temperatures further south near the Keys, if the fog holds together, would expect it to at least lift into a low stratus. Arrival at EYW would be around 06z-07z. The tempo group that describes BKN coverage still looks good. Any lingering low stratus on Monday morning should lift and scatter out further during the day on Monday. Otherwise, light northerly winds will become light northeasterly overnight. && .CLIMATE... In 1917, the daily record cold high temperature of 53 degrees was recorded in Key West. Temperature records date back to 1872. && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...Dense Fog Advisory until 5 AM EST Monday for GMZ033. && $$ Public/Marine/Fire...Haner Aviation/Nowcasts....Haner Data Collection......SD Visit us on the web at Follow us on Facebook and Twitter at:
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
943 PM EST Sun Feb 3 2019 .SYNOPSIS... Complex low pressure system will strengthen off the southeast coast this evening, then slowly lift northeast off of the North Carolina coast late tonight, finally moving away from the area Monday. A weak cold front will cross Tuesday night, stall to the south Wednesday, then lift back north Wednesday night. A cold front will move in from the west late Friday and Friday night. High pressure will build in from the north next weekend. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... As of 930 PM Sunday...Surface low continues to strengthen off the southeast NC coast, but the strengthening trend has slowed the past couple of hours. Winds remain gusty near and just off the southern coast. Latest run of the HRRR and 3km NAM has backed off the trend of showing the low retrograding toward the coast overnight and thus confidence in Wind Advisory criteria being met along the coast is a bit lower. Will keep the Advisory going to now for the potential of a few 45-50 mph gusts, especially in the Ocracoke area overnight and early Monday. Based on radar, the bulk of the steady moderate to heavy rain is along the coast from Beaufort to Buxton and north to Kitty Hawk. Have dropped the PoPs back just a tad well inland and most areas west of Highway 17 remain dry. If the low continues offshore with no retrogration, PoPs could be lowered further inland on subsequent updates. Instability is quite limited with the only lightning strikes currently being observed well south of our coast, but kept a slight chance of thunder in the forecast. Overnight lows 45-50 degrees. && .SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/... As of 230 PM Sunday...Low pressure just off the coast early Monday will slowly move eastward and further offshore through the day. Rain likely to continue along the coast Monday morning, gradually tapering off by early afternoon. Expect clouds to linger for most of the day, gradually improving from west to east late. Low level thickness values and widespread clouds support highs in the upper 50s to mid 60s, warmest inland. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... As of 245 pm Sun...Prolonged stretch of mild/dry weather through Fri then cooler next weekend. Mon night...Clouds will decrease from west to east in the evening as the surface/upper low moves away. Mostly clear skies expected after midnight. Lows will be in the mid 40s, with upper 40s Outer Banks. Tue thru Wed...High pressure passing to the south Tue will lead to dry weather and very warm highs in the lower 70s inland with 60s beaches. Weak/dry cold front will drop into the region Tue night then wash out later Wed. Highs Wed will be a little cooler with mid 50s NE coast to upper 60s/near 70 SW. Thu thru Fri...Warmest temps of the week this period as area will be in warm sector ahead of approaching cold front that will pass through Fri evening. Models dry both days and have no mention of rain. Highs Thu and Fri will be well into the 70s inland with beaches in the 60s...some record highs will be possible. Mild lows in the 55 to 60 degree range. Fri night through Sun...Cold front will pass offshore Fri night with only slight chc of showers mainly across N and NW sections. Dry and cooler with more seasonal highs in the upr 40s NE to mid 50s SW Sat and Sun. && .AVIATION /02Z MONDAY THROUGH FRIDAY/... Short Term /through Monday/... As of 940 PM Sunday...Lower ceilings (IFR/LIFR) continues at KOAJ in light rainfall. Expect to see ceilings gradually lower to MVFR or lower at KISO/KPGV over the next few hours as some light rain is possible overnight, but does not look as likely as earlier. Heavier rainfall will be confined to the coast. Expect widespread IFR ceilings through the later overnight hours with vsbys of 3-5 nautical miles. Rain comes to an end by 15-18z Monday at all sites as low lingers off the coast, but low-level moisture will lag behind it with cigs remaining sub- VFR through the end of the period. Long Term /Monday night through Friday/... As of 245 pm Sun...VFR/dry through the period. && .MARINE... Short Term /through Monday/... As of 945 PM Sunday...Low continues to strengthen off the southeast NC coast. Some question, however, to the future track of the low as most of the high-resolution models have backed away from the previous trend of showing the low retrograding toward the coast, producing Gale-force winds over most of the area waters. Did earlier issue a Gale Warning, over all coastal waters, the Sounds and Alligator River/Neuse River, although it is a bit more marginal in the northern waters and Albemarle Sound/Alligator River, but could certainly see frequent gusts to 35 knots. Conditions should begin to subside fairly quickly by midday on Monday. Seas have already reached 8 feet well off the coast of our southern CWA and seas should increase from south to north to as high as 8-9 feet overnight. Seas will subside fairly quickly Monday afternoon as the surface low moves away. Long Term /Monday night through Friday/... As of 245 pm Sun...Low pres offshore will continue moving slowly away from the region Mon night. N winds 10-20 knots will decrease overnight as the pressure gradient loosens. As high pres crosses to the S Tue expect NW to W winds only 5-10 kts. Weak cold front will sag into the region Tue night then wash out or return N late Wed. Expect light winds Tue night and Wed with period of NE winds behind front early Wed that shift back to E to SE late. Winds become SW Wed night and increase to 10-20 kts Thu ahead of approaching cold front. Winds Friday 15-20 knots south of Cape Hatteras, with 15-25 knots north. Seas will slowly subside Mon night and Tue but expect 4-7 ft seas to linger outer central and srn wtrs til Tue aftn. 3-5 foot seas Tue night and Wed will drop to 2-4 ft Thu. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...Wind Advisory until 1 PM EST Monday for NCZ095-103-104. MARINE...Small Craft Advisory until 4 PM EST Monday for AMZ136-137. Gale Warning until 11 AM EST Monday for AMZ135. Gale Warning from 4 AM to 4 PM EST Monday for AMZ130-131-150. Gale Warning until 1 PM EST Monday for AMZ152-154-156-158. && $$ SYNOPSIS...MHX NEAR TERM...CTC SHORT TERM...CQD LONG TERM...RF/HSA AVIATION...CTC/HSA/MS MARINE...CTC/CQD/HSA
Area Forecast Discussion
National Weather Service Mobile AL
1002 PM CST Sun Feb 3 2019 .DISCUSSION...See updated information for land and marine areas below. && .UPDATE...Fog is becoming more widespread over our coastal counties and also some of our interior counties, especially along and southeast of I-65. Visibilities continue to bounce around a little, but many obs have ocnly been down to 1/2 to 1/4 mile and expect at least some locations in the advised area to drop below 1/4 mile overnight (especially those areas closer to the coast). We are in the process of issuing a Dense Fog Advisory for a portion of interior southeast MS, coastal southwest AL, all of the western FL panhandle and interior sections of south central Alabama (mainly along and east of I-65). Otherwise overnight forecast remains unchanged. All products and updates out shortly. 12/DS && .MARINE... && .PREV DISCUSSION... /issued 546 PM CST Sun Feb 3 2019/ DISCUSSION...Updated for latest aviation discussion below. AVIATION... 00Z issuance...Low CIGS and patchy dense fog will return overnight. IFR to LIFR conditions can be expected at times through Monday morning. /13 PREV DISCUSSION... /issued 344 PM CST Sun Feb 3 2019/ NEAR TERM /Now Through Monday/...Weak shortwave ridging aloft will move across our forecast area this evening, before the next weak shortwave impulse embedded in westerly flow behind this feature approaches late tonight into Monday morning. A surface ridge of high pressure will remain positioned across the southeastern states and eastern Gulf of Mexico through Monday, leading to a warm and moist light southeasterly to southerly flow across our area. The primary forecast challenge for this evening into early Monday morning will once again concern the development and areal extent of fog across our region. Weak shortwave ridging developing aloft and the moist boundary layer will favor patchy to areas of fog development near the coast later this evening, before fog advects farther inland later tonight into early Monday morning. Areas of dense fog may develop around portions of the region, with SREF probabilities of visibility < 1 mile now indicated to be over 60% across a good part of the area toward 12Z. Higher resolution guidance such as the HRRR and RAP tend to favor fog development over our eastern zones and far southwestern portions of the area late. We think the potential is there for areas of dense fog, but it is currently difficult to delineate a specific area for a Dense Fog Advisory inland, so will hold off and let later shifts continue to assess this potential. A fairly dry airmass underneath weak shortwave ridging aloft support a dry forecast across the region this evening. However, increasing deep layer moisture and weak ascent ahead of the approaching shortwave impulse will favor the development of isolated to scattered rain showers late tonight into Monday. We will have a slight chance of rain in the forecast over our central and western zones after midnight tonight, and also keep 30-40% POPs in place over a good part of the area during the day Monday. Temperatures will continue to average above normal tonight and Monday, with lows tonight mostly in the 50s, with highs Monday expected to reach the upper 60s near the coast and lower 70s inland. /21 SHORT TERM /Monday night Through Wednesday night/...The upper pattern over the Conus becomes more amplified through the Short Term, as an upper shortwave system moves over the western Conus, and an upper ridge builds north along the East Coast from upper level high pressure building over the Gulf of Mexico. A surface ridge develops and builds west over the northeastern Gulf coast, bringing a more organized southerly flow and continued influx of Gulf moisture to the forecast area. A passing shortwave will bring chances of rain to the forecast area later Monday night into early Tuesday night. Looking at the model soundings with this shortwave`s passage, enough instability is present to warrant adding thunder wording for Tuesday. Wednesday/Wednesday night are expected to be generally precipitation free, with building high pressure dominating. With the increased moisture levels, fog development is again likely Monday and Tuesday nights. Have added general areas of fog wording for now. Increasing water temperatures south of the Gulf coast will decrease the likelihood of dense advection fog developing, with best chances remaining over the cool waters of area bays. Temperatures increase to well above seasonal normals over the forecast area as the upper ridge builds into mid week. Overnight lows generally in the low to mid 60s expected, with highs in the low to mid 70s expected Tuesday, mid to upper 70s Wednesday. /16 LONG TERM /Thursday Through Sunday/...As the western Conus upper system moves east over the Southern/Central Plains Thursday, the East Coast upper ridge begins to deflect the system northeast. A surface low developing over the Plains with this system moves northeast, with a trailing cold front moving over the forecast area Thursday night into Friday morning. Difference in the timing of this front`s passage has decreased significantly, so have greater confidence than previous days with this portion of the forecast. General rain showers are expected, with any upper support remaining well north of the forecast area and little to no instability showing in the model soundings. Ahead of the front, temperatures for Thursday/Thursday night are again expected to be well above seasonal levels. Friday night through Saturday night, around to a bit below seasonal temperatures are expected. Sunday into Sunday night, a passing shortwave shifts surface high pressure over and east of the forecast area, bringing a return of southerly flow and temperature rising back above seasonal normals. /16 MARINE...The warm and moist pattern will continue to support patchy to areas of fog development across portions of the marine area, primarily along the cooler bays/sounds and near shore coastal waters each night and in the morning through Wednesday. A Dense Fog Advisory will go into effect again for Mobile Bay, the Mississippi Sound east of Pascagoula, and the adjacent coastal waters out 20 nm starting this evening and continuing through Monday morning. Otherwise, a surface ridge of high pressure will remain positioned across the southeastern U.S. and the eastern Gulf of Mexico through the middle of the week, leading to a light to occasionally moderate onshore flow across the marine area. The next cold front currently looks on track to push across the marine area around the early Friday morning time frame, with stronger offshore flow expected to return Friday into Saturday following the passage of the front. /21 && .MOB WATCHES/WARNINGS/ADVISORIES... AL...Dense Fog Advisory until 9 AM CST Monday for ALZ056-059-060- 261>266. FL...Dense Fog Advisory until 9 AM CST Monday for FLZ201>206. MS...Dense Fog Advisory until 9 AM CST Monday for MSZ078-079. GM...Dense Fog Advisory until 9 AM CST Monday for GMZ630>636-650-655- 670-675. && $$ This product is also available on the web at:
Area Forecast Discussion
National Weather Service Spokane WA
703 PM PST Sun Feb 3 2019 .SYNOPSIS... Rain and snow this afternoon will transition to all snow as an arctic boundary slips in from the north this evening and overnight. Very cold temperatures are expected to arrive early next week as a cold Canadian air mass invades the region. This will likely deliver the coldest temperatures of the winter with highs in the teens and 20s and lows in the single digits. This cold will persist through most of next week, while light snow chance will increase later in the week. && .DISCUSSION... Additional evening update to increase pops near the East Slopes North Cascades, Wenatchee area, and Waterville area to coax the zones to put snow accumulations for up to 1 inch for the rest of tonight into that part of the forecast to account for the upslope flow that will start snow falling there later tonight. /Pelatti && .AVIATION... 00Z TAFS: Complex weather pattern consisting of disturbances pinwheeling outward and ahead of an area of low pressure moving south along the coast clutter overhead of the aviation area over Eastern Washington and North Idaho at times with modified polar continental air coming down from the north. Have relied on the mesoscale models such as the latest HRRR and the 18Z NAMNST to attempt to time the precipitation brought about by these disturbances as the pass across portions of the aviation area. As a result some MVFR/IFR ceilings and visibilities remain at various times due to the precipitation and possibly due to some of the leftover low stratus that may remain in the lowlands and valleys In addition tomorrow afternoon some of the modified polar continental air will seep further south thru the north to south oriented passes and bring about a more robust low level north/northeast wind. The drier air associated with this northerly flow should help dry out the low level boundary layer and erode stratus and make it way less likely to reappear. /Pelatti && .PRELIMINARY POINT TEMPS/POPS... Spokane 15 23 12 22 8 22 / 80 20 20 10 0 0 Coeur d`Alene 14 21 12 22 7 22 / 80 20 20 10 0 0 Pullman 23 31 18 23 10 22 / 60 60 60 30 0 0 Lewiston 31 38 25 28 15 27 / 70 60 50 40 0 0 Colville 16 29 8 27 4 26 / 80 20 10 0 0 0 Sandpoint 12 19 11 22 7 22 / 80 20 10 10 0 0 Kellogg 14 21 12 22 9 22 / 80 60 50 30 10 10 Moses Lake 25 31 18 28 13 27 / 20 20 20 0 0 0 Wenatchee 23 27 17 26 11 26 / 70 40 10 0 0 0 Omak 18 24 9 23 8 24 / 40 20 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...Winter Weather Advisory until 9 AM PST Monday for Northern Panhandle. Winter Storm Warning until 9 AM PST Monday for Central Panhandle Mountains. Winter Storm Warning until 1 AM PST Tuesday for Lewis and Southern Nez Perce Counties. Winter Weather Advisory until 7 AM PST Monday for Lewiston Area. Winter Weather Advisory until 9 AM PST Monday for Coeur d`Alene Area-Idaho Palouse. WA...Winter Weather Advisory until 7 AM PST Monday for Lower Garfield and Asotin Counties. Winter Weather Advisory until 1 AM PST Tuesday for Northeast Blue Mountains. && $$
Area Forecast Discussion
National Weather Service Pueblo CO
537 PM MST Sun Feb 3 2019 .UPDATE... Issued at 537 PM MST Sun Feb 3 2019 Due to decreasing winds and snow, cancelled fire weather, winter weather and high wind highlights across southern Colorado. && .SHORT TERM...(This evening through Monday) Issued at 344 PM MST Sun Feb 3 2019 ...Winds and snow tapering down this evening... Upper trof axis has crossed the front range mountains this afternoon and brought strong gusty winds to much of the southeast mountains lower elevations west of I-25. Faired better in sampling the high wind gusts in El Paso and eastern Teller county as the trof axis moved across and mixing was able to tap stronger winds aloft. Down south...was able to find several reports in the 60 to 80+ mph range in private mesonet sensors...but most of the RAWS(except for Red Creek) and METARs sites stayed just below high wind criteria. Did get a report of a tree blown down in Westcliffe and a couple reports from spotters of very strong winds...but no firm measurement of wind gusts there. La Veta area also appeared to have seen some of those stronger gusts. Quick look at cross sections from this morning showed mountain wave may have stayed up higher than originally thought with winds at mountain top level pickup up a little too late just as we lost the mountain top stable layer across southern areas. Event then transitioned to more of a downward forcing/mixing behind the trough axis and although our highest wind gusts have likely already been achieved...will keep the current high wind highlight going for another our or two as HRRR still suggests some strong gusts will be possible through 00z. Suspect that next shift will be able to take the warning down at 6 PM. Have also been meeting critical fire weather conditions along the I- 25 corridor at times...particularly across El Paso and Las Animas counties. Relative humidity has been very close to the 15 percent threshold in Pueblo County and parts of Huerfano county as well and wind gusts are still expected to stay gusty for a couple more hours Red Flag Warning will also remain in tact. Meanwhile...webcams have been showing heavy snow across the eastern San Juan mountains all day with Wolf Creek ski area reporting 10 inches of snow accumulation so far. Visibilities are starting to come up in the past think expiration around 6 PM will still work out. For the rest of tonight and Monday...will keep at least some scattered snow showers going across the Continental Divide as southwesterly flow will keep sending waves of moisture into the area. Best orographics will continue to be across the eastern San Juan mountains where additional accumulations of 2 to 4 inches can be expected through Monday. Lighter amounts in the 1 to 2 inch range will be possible across the Sawatch and Mosquito ranges where southwest flow is not as orographically favored but some lingering instability and moisture will aid in rounds of light snow going from time to time. Cold front will back door into far eastern plains tomorrow afternoon...but still expecting rather mild temperatures again for Monday with less wind. Southeast plains will top out in the 50s and lower 60s...with 40s and 50s for most of the valley locations and 20s and 30s for the mountains. It appears the San Luis valley could tap sufficient wind again on Monday to warm above freezing, though MaxT forecast there is certainly challenging. Have kept a conservative mid to upper 30 forecast for that area...but this could be too warm if winds don`t kick in as expected. -KT .LONG TERM...(Monday night through Sunday) Issued at 344 PM MST Sun Feb 3 2019 Monday night-Tuesday...Southwest flow aloft increases across the area Monday night and Tuesday, ahead of another system digging into the Great Basin. Models continue to differ on strength of the flow as well as the location of induced surface low across the Eastern Plains, though the latest GFS, NAM, and EC are starting to come together on the potential for a cooler airmass to sneak into portions of the Southeast Plains late Monday night, as surface high pressure builds through the Northern and Central High Plains. With a developing surface low near La Junta, could see some fog developing east across Prowers and Kiowa Counties into early Tuesday morning, as moist easterly low level flow develops. Highs on Tuesday could also be lower in the mid 40s to lower 50s east of La Junta, with highs in the mid to upper 50s along with breezy west to southwest winds west of La Junta. Otherwise, should see occasional light snow continuing across the Continental Divide, with generally light accumulations of 1 to 4 inches, greatest across the Southwest Mts. Tuesday night-Thursday night...Latest models are coming into to better agreement of strong southwest flow developing across the region through the day Wednesday, as the Great Basin system starts to lift out across the Rockies. This system is then progged to continue across the Rockies Wednesday night, and into Northern and Central High Plains on Thursday, with cool northwest flow in its wake. With that said, will continue to see light to moderate snow across the ContDvd Tuesday night and Wednesday, and will likely need winter weather highlights with low end warning criteria possible through this timeframe. Chances of snow to spread across the High Mountain Valleys through the Southeast Plains Wednesday night and Thursday morning, with much cooler temperatures areawide expected on Thursday behind the passing system. Current forecast would keep the best chances of snow across northern portions of the cwa, especially across the Palmer Dvd late Wednesday night and early Thursday, though quick movement of the system would keep accumulations on the light side. Will also see strong and gusty southwest winds over and near the higher terrain Tuesday night, which look to spread east across the Southeast Plains on Wednesday, leading to the potential for critical fire weather conditions once again on Wednesday, mainly along and west of the I- 25 Corridor, along with the potential for a big temperature bust across the Southeast Plains, if the systems associated prefrontal trough/low is further south and the strong southwesterly winds do not develop across the area. Still a lot of questions to be answered through this timeframe. Friday-Sunday...Drier and warmer weather pattern expected into Saturday, as upper level ridging builds across the region once again. Another embedded system could bring snow chances to the ContDvd again later Saturday night and Sunday. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 344 PM MST Sun Feb 3 2019 Conditions will remain VFR at the TAF sites tonight...though with some melting snow at KALS there is a slim chance for some brief VFR to MVFR Vis in patchy ground fog overnight. Think this will be an outlier potential though as winds aloft are forecast to remain fairly strong. May include some VFR fog towards morning as boundary layer may deepen sufficiently to allow some shallow fog to form. KCOS and KPUB will continue to see some strong westerly winds through 00z with gusts up to 35 kts at times...however winds will be on the decrease. Expect VFR conditions to continue into Monday with winds increasing from the south to southeast in the afternoon with some gusts to around 20 kts. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$