Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/06/19

Area Forecast Discussion
National Weather Service Dodge City KS
546 PM CST Tue Feb 5 2019 ...Updated Aviation Section... .SHORT TERM...(This evening through Wednesday) Issued at 112 PM CST Tue Feb 5 2019 As of 1 pm there was still a large area of stratus and fog across southwest Kansas. Visibilities below 1/4 mile were also being reported in several locations across southwest. RAP and NAM BUFR soundings do indicate that conditions should be improving but given the high clouds overspreading the stratus and fog this afternoon clearing trend may be overdone. As a result will issue a dense fog advisory for southwest Kansas this afternoon and early tonight. Models this afternoon remain in good agreement with some brief improving conditions early tonight but after midnight the potential for freezing fog and even some freezing drizzle is expected to redevelop. The area most favorable for the freezing fog and light freezing drizzle northeast of a Garden City to Meade line based on where the better lift and deeper moisture will be located early Wednesday morning. In this region the conditions late tonight and early Wednesday morning will be similar to what we had earlier today west of Dodge City. Areas of Freezing fog and light freezing drizzle can be expected with minor ice accumulations between 3 am and noon Wednesday. As a result will be issuing a winter weather advisory for late tonight and Wednesday for this region. Further southwest some freezing fog also can not be ruled out, especially north of a surface boundary that is forecast to be located between Dodge City and Elkhart. Later shifts may wish to monitor this area for possible inclusion into the winter weather advisory should the depth of the moist layer becomes deep enough for some light freezing drizzle. The surface boundary is still forecast to lift north as a warm front during the day on Wednesday but confidence is not high on how far north this boundary will move before returning back south as a cold front Wednesday night. Based on the cold air and cloud cover forecast north of this boundary tonight and early Wednesday morning will be favoring the further south solution from the models. This would keep Garden City and Dodge City in the cold air so highs once again for much of southwest and all of north central Kansas will be confined to the 20s and 30s. South of this boundary, in the Elkhart and Liberal areas, the highs Wednesday afternoon are expected to be 30 to near 40 degrees warmer. Could easily see highs in the mid to upper 60s in extreme southwest Kansas near the Oklahoma panhandle border. .LONG TERM...(Wednesday night through Tuesday) Issued at 241 PM CST Tue Feb 5 2019 A strong cold front is still on track to crossing southwest Kansas Wednesday night as an upper level trough exits the Rockies and moves out into the Central Plains. Strong gusty north winds and colder air will begin to invade southwest Kansas towards daybreak on Thursday and then continue through the day. There will even be a chance for some light snow Wednesday night as the upper level trough passes western Kansas and the colder air returns. At this time it appears the better chances for any measurable snow accumulations will be across north central Kansas. The snow accumulation near and north of the I-70 corridor is still expected to be light and average be around one half of an inch or less. In addition to the chance for light snow Wednesday night the gusty north winds will produce some bitter cold wind chills across southwest and north central Kansas early Thursday morning. Wind chill values of zero to around -10 degrees still look likely, especially north of Dodge City. Thursday will be the coldest day of the work week with highs Thursday afternoon mainly in the 15 to 25 degree range. Wind Chills will be as low as zero to 5 degrees. An upper level ridge will build across the Rockies and out into the Plains over the weekend as a trough of low pressure at the surface develops along the lee of the Rockies. This continues to support some warmer temperatures for western Kansas over the weekend, Highs rebounding back into the 40s will be likely with even some low to mid 50s being possible Sunday afternoon. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 542 PM CST Tue Feb 5 2019 Widespread VLIFR flight category is forecast, including GCK, DDC, and LBL terminals in this persistent freezing fog event. We expect the shallow cold front at the surface to remain nearly stationary through much of this forecast period, so persistence is the best forecast method through at least the first half of Wednesday. HYS is far enough northeast from the front itself tonight to remain in VFR/MVFR flight category, but they too should deteriorate down to IFR some time overnight or very early Wednesday morning as warm, moist advection increases just off the surface in advance of the next storm system. && .PRELIMINARY POINT TEMPS/POPS... DDC 23 39 10 24 / 10 10 10 0 GCK 22 34 9 22 / 10 10 20 0 EHA 29 62 15 29 / 0 0 0 0 LBL 27 64 15 26 / 0 0 0 0 HYS 15 27 10 17 / 20 20 30 0 P28 26 44 17 27 / 20 20 10 0 && .DDC WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 9 PM this evening to 3 PM CST Wednesday for KSZ030-031-043>046-063>066-077>081-088>090. Dense Fog Advisory until 9 PM CST /8 PM MST/ this evening for KSZ061>063-074>078-084>088. && $$ SHORT TERM...Burgert LONG TERM...Burgert AVIATION...Umscheid
Area Forecast Discussion
National Weather Service Duluth MN
540 PM CST Tue Feb 5 2019 .UPDATE... Issued at 540 PM CST Tue Feb 5 2019 Persistent lake effect snow bands continue to move into the Twin Ports area and along the North Shore this evening. Snowfall spotters report 1 to 2.5 inches so far. There remains significant low level shear but it is having little affect on the snowband so far. Forecast soundings show a favorable profile for dendritic snow growth through around 3600 feet through the night. We will be issuing a Winter Weather Advisory for tonight for Coastal Lake into southern Saint Louis Counties. Large scale lift will be on the increase this evening and will add to the snowfall. The RAP does show the low level flow veering a bit mid to late evening which may shift the heavier snow north of the Twin Ports for a time but then the wind backs again late. As subsidence increases as the shortwave moves off late tonight the lake snow band should weaken. We`ll have to keep an eye on any areas that see the band persist as snow totals will add up quick and it`s possible an upgrade to a warning may be needed. && .SHORT TERM...(This evening through Wednesday) Issued at 344 PM CST Tue Feb 5 2019 A round of light snow late today into this evening for much of the Northland, then a break in the snow overnight before the next round on Wednesday. Parts of northwest Wisconsin can expect locally higher snowfall amounts, especially across Price County where around 2 to 5 inches of snow is expected today due to band of stronger frontogenetical lift across central Minnesota into northern Wisconsin, driven by a weak mid-level shortwave trough moving across a broad area of low level warm air advection, all under an area of jet divergence aloft. On the synoptic scale a mid/upper level longwave trough over the southwest is resulting in southwesterly flow at mid and upper levels, resulting in numerous weak mid-level shortwave troughs to eject into the Great Plains and Upper Great Lakes region. As the main longwave trough axis crosses into the southern High Plains tonight, a surface low will begin to deepen in response over Missouri. Ahead of this low formation, southeast to east winds at low levels across the Upper Midwest will lead to continued weak warm air advection, with easterly winds over Lake Superior in an environment with increasing moist low levels will be favorable for weak lake-effect snow showers along the western Lake Superior shoreline. An elevated warm frontal zone will lift north across northern Minnesota overnight producing a broad area of light snowfall in this environment, but due to the weak nature of the forcing snowfall amounts will be light, less than an inch for much of northern Minnesota with around 1 to 2 inches for areas along the Lake Superior shoreline, including in the Twin Ports. Across northwest Wisconsin, a band of moderate to at times heavy snowfall is approaching from the south in an environment with strong warm air advection. Snowfall amounts have been increased a bit from the previous shift based on changes in short-range guidance and upstream obs which support the possibility for visibility less than a half mile and resultant snowfall amounts possibly approaching six inches in southern Price county. Elsewhere in northwest Wisconsin amounts will range from 2 to 5 inches within the Winter Weather Advisory, less than 2 inches outside the Advisory area. Snowfall will be most intense this evening, then quickly taper off from west to east as warm air advection rates, and thus the frontogenesis process, diminish. .LONG TERM...(Wednesday night through Tuesday) Issued at 344 PM CST Tue Feb 5 2019 A low pressure system out of the rockies will bring the next chance for significant snow accumulation for the CWA beginning Wednesday evening and continue through Thursday. A Winter Weather Advisory has been issued for the CWA with the potential for 5-7" of snow over a 36 hour period. Some areas may see higher amounts in localized snow bands. As the low moves out on Friday, high pressure and cold air settle back into the northland with windchill advisories likely needed on Friday and Saturday morning. Temperatures will begin to rise early next week fueled by warm air advection out in front of weak low level trough that will bring a round of light snow showers to the area. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 540 PM CST Tue Feb 5 2019 A shortwave and lake processes will bring snow to portions of the Northland tonight along with widespread MVFR conditions. The visibility will drop to a half to 3 miles in the snow but improve late tonight into Wednesday morning. The lowest visibility will occur over portions of northern Wisconsin and along the North Shore into the Twin Ports. Another round of snow will affect much of the region Wednesday night. && .PRELIMINARY POINT TEMPS/POPS... DLH 7 18 10 14 / 80 40 80 80 INL -2 14 1 7 / 60 60 80 70 BRD 4 20 9 13 / 80 50 80 70 HYR 9 26 16 20 / 100 20 80 80 ASX 9 22 15 18 / 90 30 80 80 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...Winter Weather Advisory from 6 PM Wednesday to 6 PM CST Thursday for WIZ001>004-006>009. Winter Weather Advisory until midnight CST tonight for WIZ003- 004-008-009. Winter Weather Advisory until 10 PM CST this evening for WIZ006- 007. MN...Winter Weather Advisory from 6 PM Wednesday to 6 PM CST Thursday for MNZ010>012-018>021-025-026-033>038. LS...None. && $$ UPDATE...Melde SHORT TERM...JJM LONG TERM...JJM/TLV AVIATION...Melde
National Weather Service Kansas City/Pleasant Hill MO
525 PM CST Tue Feb 5 2019 .Discussion... Issued at 306 PM CST TUE FEB 5 2019 Well...long awaited freezing drizzle/freezing rain event well underway this afternoon as latest regional radar images show plenty of returns streaming northeast from south-central KS. This is occurring as southwest midlevel flow becomes better established over the central U.S., which will allow for an active corridor of passing midlevel impulses through Wednesday night/early Thursday. Closer to the surface, main front that blew through yesterday remains stalled down across Oklahoma and Arkansas, with latest MSAS analysis showing an inverted trough extending north across western and central Missouri. With time, winds in the 925-850 hPa layer are expected to increase, which will lead to increased isentropic ascent over our region, and latest radar imagery seems to support this line of thinking. So...we`re looking at several hours of light freezing drizzle and rain this afternoon and evening, before we see a temporary reprieve later tonight as surface ridging to our northwest builds south over our region. This should allow drier air to surge southward during the overnight hours, which presumably would lead to a few dry hours during the overnight before the next upstream wave approaches by daybreak. Speaking of the next wave, latest HRRR and RAP show the next batch of precip approaching the western zones by 12z Wednesday. Considering with ridge will be firmly established over our region, much, if not the entire forecast area should be below freezing as this secondary wave approaches. That said, expect deteriorating conditions once again for the AM commute, which could certainly be magnified with if road surface treatments aren`t able to make a dent in this afternoon/evening`s slippery conditions. After 12z Wednesday, precip is expected to just continue overspreading the region through the day, which will lead to additional icing across the area. To complicate Wednesday`s forecast even more is the fact that the main surface low across western Kansas will begin moving east with time, which in a perfect world would lead to warming temps through the afternoon/evening as warm air advection increases. But, the NAM and Canadian continue to be insistent that the freezing line will barely lift north into our forecast area during the afternoon, and considering the aforementioned surface ridge axis and continued northerly/northeasterly sfc winds, its certainly possible that much of our forecast area will struggle to warm above freezing during the day on Wednesday. That said, have trended downward with temps for tomorrow which obviously has increased the ice accumulations to some degree. By Wednesday night, we should see the main sfc low passing to our south which should allow the freezing line the opportunity to finally lift north into portions of our area. Right now, it current looks like areas along/east of Route 63 and south of Route 50 will stand the best chance of climbing above freezing, with areas north and west remaining below the freezing mark. Was tempted to extend the winter wx advisory through 18z Thursday with this forecast package, however decided against it after considering the temperature uncertainties later tomorrow afternoon and evening. Will allow the overnight shift another opportunity to look at model surface temperature trends before making the hard and fast decision to a new advisory or local expansion. All told, the event looks like a solid advisory event with light winds and drizzle occasionally mixing in with freezing rain which will hopefully keep ice accumulations below ice storm warning criteria (0.25"). Typically we`d see higher amounts if the winds were strong, but winds through this event are mostly expected to remain below 12 kts. Plus, ice accumulation efficiency typically decreases when you have a mix of both freezing rain and freezing drizzle, which it appears we`ll definitely have with this scenario due to an increased potential for some runoff. That said however, this system has the potential for major impacts on the region, mainly from the length of duration perspective as this system will impact us for a solid 50 hours or so. Event total ice accums up to a quarter inch will be possible before all is said and done, but fortunately weak winds and lower radial ice accumulations on power lines and tree limbs will hopefully prevent widespread power outages and other problems from occurring. Beyond this, cold high pressure is expected to build south into the lower Missouri Valley with single digit low temperatures expected both Friday and Saturday mornings. These cold temps should be shortlived however as ridging develops downstream over the central U.S. as another trough starts moving through the American West. && .Aviation...(For the 00Z TAFS through 00Z Wednesday Evening) Issued at 518 PM CST TUE FEB 5 2019 Light freezing drizzle will persist through the early evening hours, along with IFR ceiling heights. This activity should begin to dissipate around 03Z with a notable improvement in visibilities. Ceiling heights should improve slightly overnight to MVFR before a subsequent round of freezing drizzle approaches the area early Wednesday morning. This activity may be intermittent at times through much of the day, before an eventual transition to freezing rain after sunset Wednesday. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...Winter Weather Advisory until noon CST Wednesday for KSZ025-057- 060-102>105. MO...Winter Weather Advisory until noon CST Wednesday for MOZ001>008- 011>017-020>025-028>033-037>040-043>046-053-054. && $$ Discussion...32 Aviation...Welsh
Area Forecast Discussion
National Weather Service Wichita KS
605 PM CST Tue Feb 5 2019 ...Updated Aviation Discussion... .SHORT TERM...(This evening through Friday night) Issued at 412 PM CST Tue Feb 5 2019 A complex and challenging forecast is in store over the next 48 hours, mainly centered around potential weather weather impacts. Surface analysis this afternoon depicts a warm front extending from the High Plains, southeast into the southern Plains, then on east across the Ozarks/Mid-south region. There is an impressive temperature gradient along this front. Case in point, Coffeyville is currently in the low 30s, while just south of Tulsa, it is in the low 70s. Visible satellite imagery suggests the section of the front over the Ozarks is lifting north faster than it is back to the west over Oklahoma. This may be due, in part, to a weak SFC low/wave moving NE through that area. But, for now, we expect the front to stay south of our forecast area and have trended the forecast to reflect this. North of the front, a well-established northeast low-level flow beneath a stout inversion (with warm layer temps of 5-10C) is allowing a shallow layer of sub-freezing temperatures to remain entrenched over much of our forecast area. In fact, temperatures have shown little, if any, movement since this morning. Models have really struggled with temperatures this afternoon and the forecast was leaned heavily towards the HRRR, NAM, RAP which have had the best handle thus far. This suggests nearly steady temperatures through tonight, before some potential warming by Wednesday afternoon. Regarding precipitation, water vapor and model data indicate several upper level waves embedded within a 140kt SW jet. One such wave is moving through eastern Kansas at this time as evidenced by a band of steadier precip. This has been a mix of rain and freezing rain, depending on SFC temp. In the wake of that wave, precip rates should decrease with more of a drizzle/freezing drizzle/fog type scenario expected. The next wave comes through tonight. Once again, broad WAA and isentropic upglide combined with a deepening moisture profile should allow areas of freezing drizzle to redevelop. Of note, moisture tonight looks a bit greater/deeper than what we saw this morning and this may allow for a period of freezing rain as opposed to freezing drizzle, especially along and east of the Kansas Turnpike. Of note, too, a plume of steeper mid-level lapse rates above the inversion may allow for some thunder/convective elements tonight should a deeper layer of moisture be realized. This would only act to increase freezing rain rates for a time should this occur. Based on all of the above, we have upped ice accretion areawide, with most areas seeing a few hundredths of ice to as much as 0.10-0.15" (east of the Turnpike). With the cold temperatures in place, it will not take much ice to create difficult travel and for this reason, we have expanded the Winter Weather Advisory to include all of our forecast area. We will also be extending the Advisory into early Wednesday afternoon. One quick note regarding precip type. While the warm layer aloft very much supports freezing rain/freezing drizzle, surface temps across central Kansas may actually be cold enough for some dendrite production, with some snow possibly mixing in there. While most of the focus during this time is the winter impacts, we cannot ignore the thunderstorm potential across far SE KS. A SFC low will drop southeast out of the High plains Wednesday afternoon, then cut east along the KS/OK border Wednesday evening/night. Thinking the front will stay just south/east of our CWA, keeping the stronger instability there as well. However, thunderstorms developing ahead of the SFC low may clip far SE KS, but we do not expect any severe weather at this time due to a lack of better instability. Martin .LONG TERM...(Saturday through Tuesday) Issued at 412 PM CST Tue Feb 5 2019 Southwest flow aloft looks to continue into next week, with additional upper level shortwaves traversing the region. Despite the progressive nature, each wave may continue to afford the opportunity for additional rounds of overrunning precipitation, including some winter weather impacts. The focus for today is on the current winter hazards, so stay tuned for future updates on potential impacts. Martin && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 540 PM CST Tue Feb 5 2019 The main aviation concerns across central, south central, and southeast Kansas over the next 24 hours will continue to be low clouds, fog, and freezing drizzle throughout the period. Latest satellite, radar imagery, and surface observations show that much of the freezing drizzle that impacted the area today has moved off to the east along with more favorable isentropic upglide. This has produced a lull in precipitation across the area for the most part, though some lingering freezing drizzle will be possible at KCNU early in the period. Visibilities have generally improved to P6SM, also with the exception of KCNU. However, this evening and overnight tonight low level isentropic upglide and warm air advection will increase once again, and the setup looks to produce more freezing drizzle chances beginning early Wednesday morning and lasting throughout the rest of the period, with potentially heavier precip in southeast Kansas. Have fairly high confidence in low clouds lingering throughout as well, though KRSL and KGBD may see a very brief break in the short term. && .FIRE WEATHER... Issued at 412 PM CST Tue Feb 5 2019 Precipitation and light winds will limit any fire weather concerns over the next couple of days. Breezy/windy conditions are expected Thursday and again over the weekend, potentially with at least some increase in fire concerns. Martin && .PRELIMINARY POINT TEMPS/POPS... Wichita-KICT 25 37 21 24 / 40 30 20 10 Hutchinson 23 33 18 22 / 30 30 20 10 Newton 23 33 19 21 / 30 30 20 10 ElDorado 26 35 22 23 / 40 40 20 10 Winfield-KWLD 29 43 26 27 / 40 50 20 10 Russell 18 25 14 18 / 20 30 30 10 Great Bend 21 30 15 20 / 30 30 20 10 Salina 20 26 16 20 / 20 30 40 10 McPherson 21 30 17 20 / 20 30 30 10 Coffeyville 32 49 33 33 / 60 70 50 20 Chanute 28 41 29 29 / 50 60 40 20 Iola 27 40 29 29 / 40 60 40 20 Parsons-KPPF 31 46 32 32 / 50 60 50 20 && .ICT WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 3 PM CST Wednesday for KSZ032-033- 047>053-067>072-082-083-091>096-098>100. && $$ SHORT TERM...RM LONG TERM...RM AVIATION...TAV FIRE WEATHER...RM
National Weather Service Wilmington OH
832 PM EST Tue Feb 5 2019 .SYNOPSIS... A trough of low pressure will orient itself along the Ohio River late tonight and Wednesday. As a surface low moves east and along it early Thursday, a boundary will stretch out south of the Ohio River. This boundary will then lift north towards a vigorous low pressure center in Michigan, followed by a strong cold front moving southeast through the region Thursday night. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... Plenty of things to keep an eye on for the overnight into Wednesday. The 06.00Z KILN sounding sampled an extremely shallow wedge of near-surface cold air underneath a very strong/warm inversion /+12C at 925mb/ with moderate veering /warm advection/ flow atop the inversion. 00Z surface analysis placed a strong thermal gradient across southern Ohio back to the southwest into Arkansas. As a representation of this - it`s in the mid 30s across central Ohio - and in the mid 50s three counties away to the south along the Ohio River. Widespread low clouds and fog were in place along and on the cool side of the thermal gradient - just about the entire WFO ILN CWA. Initial arm of warm advection in the 925-850mb layer was inducing decent isentropic ascent in the 290-295k layer. A strengthening /albeit still weak overall/ moisture transport signal could be seen in RAP data when plotting MTV on the isentropic surfaces - and in reality - advection of mid 50s temps and dewpoints up the slope where it`s still in the mid 30s spells good lift/saturation. Expect the current batch of rain over southwest Ohio to continue to spread northeast as it slowly outruns the better isentropic ascent and weakens later this evening. Made some adjustments to the rain chances in this small area of the central ILN CWA to increase PoPs. Attention then turns upstream to growing area of rain/showers and a few thunderstorms over southwest Indiana and northern Kentucky. Plenty of lightning in this activity, and forecast RAP/HRRR soundings in the ILN CWA after midnight show that as moisture increases amidst residual mid-level lapse rates of 7C/km, some elevated instability develops from west to east across the forecast area. Thus, expect a few rumbles of thunder could be heard tonight especially in our Indiana/western Ohio counties when the next surge of moisture arrives. This moisture/lift tied to weak shortwave energy ejecting out into the Ohio Valley well downstream of longwave trough moving through the western US. Expect the period after about 06Z to feature increasing rain/showers and a few thunderstorms as renewed burst of lift and moisture transport focus into the forecast area, with rain becoming more widespread by later in the night when the brunt of the forcing arrives. Don`t expect any hydro issues with this activity tonight unless a few convective elements train over localized areas. Also watching our far northern areas /Bellefontaine Ridge/ closely to be sure they remain above freezing - right now there is not an expectation of needing to insert any freezing rain into the forecast. In terms of fog - it`s everywhere out there - but so far impacts aren`t significant. It`s a widespread 1/2SM to 3SM fog for most areas, and is expected that waves of rainfall will keep things from getting too dense. Inserted widespread fog into the forecast to account that it`s showing up in some capacity on most webcams and observations, but don`t expect much impact to travel except of patches of dense fog in higher terrain areas. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... Any scattered shower activity southeast of the I-71 corridor will increase in coverage quickly during the morning, with categorical pops expected northwest of the interstate at daybreak. Temperatures will rise into the 50s to lower 60s on Wednesday, and there could be a tight gradient to the north with a chance of cooler readings if the winds stay northeast and the surface low has a more southerly track. Overnight will see another slow fall in temperatures with a rise late overnight as winds once again shift southeast and south. Expect lows to be 5-8 degrees off of the highs on Wednesday, generally in the upper 40s north to mid and upper 50s south. A surface low will track northeast along the Ohio River/I-71 corridor during the day. As it exits northeast in the afternoon, a lull in this rain will occur. Enough lift ahead of this surface low may be present to support thunder through the course of the day, this generally lies south of a Brookville- Wilmington-Chillicothe line. The thunder chances will wane in the afternoon as the surface low exits east, and a lull in the more continuous rainfall is expected for the late day and evening hours. Models are not in the best of agreements here and the NAM is suggesting a more continuous moderate rainfall southeast of the I-71 corridor. The bulk of the models all see some break behind the surface wave, affecting the majority of the ILN CWA Wednesday afternoon and evening. This break is short lived, and winds quickly shift back to the southeast and south, recharging the lower atmosphere ahead of the next wave of low pressure. This is going to initially be a warm front lifting north through the Ohio Valley ahead of the next vigorous low that will be spoken to in the extended forecast section. Given this rain and subsequent rain expected Thursday, a flood watch seems to be the better course of action today. Precipitable water values of 1.25 to 1.5" are 3 to almost 4 standard deviations above the normal (~1/3") for this time of year which happens to be the climatological minima for PWAT. This abundant moisture is being pulled in on southwesterly low level winds in excess of 50-70kt during the day Thursday. && .LONG TERM /THURSDAY THROUGH TUESDAY/... Multiple surface lows and enhanced periods for rain will effect the Ohio Valley this week, offering the potential for flooding. In the wake of a sfc wave moving thru Wednesday night the front temporarily lays out E-W across Kentucky. Vigorous negatively tilted mid level shortwave to eject northeast from the Upper Mississippi Valley and into the Great Lakes Thursday/Thursday night time frame. The stalled front to lift north with the Ohio Valley getting into the warm sector. Favorable moisture transport will exist with precipitable water values expected to be above 1.5 inches ahead of an approaching cold front Thursday afternoon. Will continue categorical pops with heavy rain possible. Also, marginal instby works into the far south Thursday, so will continue a mention of a chance for thunder. In the warm sector expect very mild highs on Thursday from the upper 50s northwest to around 70 southeast. The cold front to sweep east through the area Thursday night with the deep moisture shifting east of the area. There may be a brief period of snow prior to ending early Friday but the model trends show the favorable lift/moisture shifting east prior to temperatures becoming cold enough for snow. Therefore, will limit the mention of snow to slight chance pops. Forecast rainfall totals for the Wednesday night through Thursday night time frame are expected to be between one and three inches with the heaviest values along and south of I-71. With saturated/frozen ground, a prolonged period of multiple rounds of rain, have issued a flood watch until 12Z Friday. The gradient tightens with gusty winds expected Thursday night into Friday with wind gusts of 35 to 40 mph possible. In strong CAA temperatures will struggle to rise much during the day on Friday and will likely drop off during the day. Expect high temperatures on Friday to range from the upper 20s northwest to the upper 30s southeast. Northwest flow develops with surface high pressure building across the area Friday and Saturday offering dry weather. Expect below normal temperatures with Saturdays highs from the upper 20s northwest to the lower 30s southeast. Flow backs with moisture returning later Sunday with the best chance across the south, closer to a frontal boundary. Surface wave forecast to track northeast from the Lower MS Vly into the Ohio Valley Monday night into Tuesday. Model solutions show spread on exact location and timing. Will ramp up pops to likely with the best threat across the south. A mix of rain and snow will be possible - changing to rain from south to north later Monday into Tuesday. Mondays highs from the mid 30s north to the mid 40s south, warming to readings ranging from the upper 30s north to the upper 40s south. && .AVIATION /01Z WEDNESDAY THROUGH SUNDAY/... Plenty of aviation concerns in the next 24 hours - and suffice it to say - conditions will not be ideal. Ongoing widespread IFR/locally LIFR conditions at 00Z across the TAF sites aren`t expected to improve much at all tonight. Warm/moist air poised just south of strong frontal thermal gradient draped across southern Ohio and Kentucky will continue to spread north tonight as a weather disturbance passes through the Great Lakes. The surge of warmth and moisture /manifested in rising temperatures and dewpoints/ will keep ceilings locked in IFR category, and may induce further lowering to widespread LIFR or even VLIFR conditions. Not surprisingly, in the cool air along/north of the boundary fog is widespread with 1SM-3SM visibility. Pockets of 1/4SM to 1/2SM are expected to continue tonight - but there is uncertainty on how expanding showers and areas of rain will impact the visibility. Think it will have some effect to keep visibility from dropping too low - but having said that - airports like DAY/ILN will be the first to succumb to dense fog given their relative higher elevation in comparison to the Columbus/Cincinnati terminals. Ongoing showers should slowly increase in coverage/intensity through the night as they spread northeast, with highest coverage/probability at Cincinnati terminals, Dayton, and Wilmington. Later in the night and especially on Wednesday morning, a large area of rain will spread over all sites with low visibilities and ceilings, and this rain will be slow to move out during the afternoon, but do expect all areas to clear somewhat from the rain in the afternoon. Only concern here is if the boundary hangs up close enough to CVG/LUK/ILN to keep showers going there well into Wed evening, which is a low confidence outcome right now, but one that is certainly seen in some of the guidance. Winds will start light from the northeast and slowly veer to southwest through the TAF cycle with some modest strengthening as the boundary lifts north, and then settles back south toward the end of the TAF period. OUTLOOK...MVFR/IFR conditions likely Wednesday night through Friday morning. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...Flood Watch from Wednesday evening through Friday morning for OHZ026-034-035-042>046-051>056-060>065-070>074-077>082- 088. KY...Flood Watch from Wednesday evening through Friday morning for KYZ089>100. IN...Flood Watch from Wednesday evening through Friday morning for INZ050-058-059-066-073>075-080. && $$ SYNOPSIS...Franks NEAR TERM...Binau SHORT TERM...Franks LONG TERM...AR AVIATION...Binau
Area Forecast Discussion...Updated
National Weather Service Saint Louis MO
1006 PM CST Tue Feb 5 2019 .UPDATE... Issued at 959 PM CST Tue Feb 5 2019 A lot going on this evening. The earlier adjustments to temperatures in central and northeast MO into west central IL are on track as winds have become northwesterly in the wake of the inverted surface trof and temps are cooling. That said the lionshare of additional rain overnight is expected to stay south of the freezing temperatures and be focused along an axis from roughly the Lake of the Ozarks through the St. Louis area to Effingham IL. Any icing within the advisory area overnight should be limited. The rain has also "scoured" out the lower visibilities from fog that had set in across east central MO into southwest IL. Portions of southeast MO into southwest IL still have locally dense fog and will have to watch this area to see if it persists, however rain will also be spreading into this area in the next few hours. Lastly elevated instability is fueling some embedded tstorms within the aforementioned precipitation axis. Issued at 656 PM CST Tue Feb 5 2019 I`ve made an update to add a few more counties in central Missouri to the winter weather advisory - Audrain, Boone, and Moniteau. Temperatures across much of Audrain and western portions of Boone and Moniteau counties remains at or below freezing, and the surface winds in these areas will be shifting around to more northerly this evening with the passage of an inverted surface trof. This will end any potential warming and may actually cool these areas by a few degrees as the freezing line retreats a tad to the east. The HRRR and RAP show this quite nicely. The overall impacts may be limited to mainly icing on elevated surfaces and rural or untreated roads. Several RWIS sensors show road surface temps from 33-37 degrees along I-70. The latest winter weather MoDOT travel map was showing partly covered roads from Mexico north and west across northern parts of Boone County. Another surge of precipitation is expected late this evening behind this initial area. Overall ice accumulations may be no more than a light glaze with southward extent in Moniteau to around a tenth of an inch in Audrain County, with amounts increasing further to the northeast. Will be keeping an eye on Pike County MO and Pike County IL where both the T and Tw are at freezing and they remain in southeast flow. Given the warm hydrometer temp and marginal surface temps in these later areas - it generally doesn`t bode well for much accumulating ice and current thinking is more like spotty light amounts. Glass && .SHORT TERM... (Through Late Wednesday Afternoon) Issued at 303 PM CST Tue Feb 5 2019 An active weather pattern will continue tonight as broad warm/moist advection will lead to an increase in coverage of precipitation this evening. While most of the precipitation should fall as a cold rain, temperatures are forecast to be just below freezing across portions of northeast Missouri and west-central Illinois. Precipitation type should be mostly freezing rain tonight in this region, though a brief period of sleet is possible within the first hour or two after onset. Precipitation should slide southeast overnight tonight behind the passage of an inverted trough. Ice accretion will not be efficient due to multiple factors including: 1) very warm water droplets making it to the surface due to a very warm/pronounced warm layer (near +10C) and 2) marginal surface temps. Because of these reasons, ice amounts within the winter weather advisory are expected to range from a light glaze to just above a tenth of an inch. The only change with the advisory was to add Ralls county in Missouri and Brown county in Illinois due to slightly cooler temperatures expected overnight tonight which led to a longer period of freezing rain. In areas that are expected to stay above freezing overnight, rain showers are likely along with a chance of thunderstorms. Brief periods of moderate rainfall are possible. Another potential problem will be fog. Current observations show widespread visibilities below 1SM across parts of the mid south. Believe the densest fog overnight tonight will focus just southeast of the CWA closer to the quasi- stationary front, but we will have to keep an eye on the northern extent of the dense fog however to see if it moves into far southern portions of the forecast area tonight. Multiple additional rounds of precipitation are likely on Wednesday as the frontal boundary lifts slightly northward with persistent low- level warm/moist advection and impulses moving from southwest to northeast between the western trough and the southeast CONUS ridge. An even larger majority of the precipitation should be a cold rain on Wednesday as surface temperatures slowly climb through the day. However, temperatures will remain near freezing especially early on Wednesday for portions of northeast Missouri so an additional light glaze of ice is likely, mainly during the morning hours. Gosselin .LONG TERM... (Wednesday Night through Next Tuesday) Issued at 303 PM CST Tue Feb 5 2019 The wet pattern will continue Wednesday night and Thursday with continued low-mid level warm air advection over a nearly stationary front which will be across southern portions of MO and IL Wednesday evening. It appears that the surface temperatures will be warm enough Wednesday night that the precipitation type will be in the form of liquid rain. There will be the threat of embedded thunderstorms, particularly across southeast MO and southwest IL where better low level moisture and instability will exist. There may be the potential for heavier rain amounts across this area as well Wednesday night and Thursday morning. With the potential for higher QPF over areas which will see several rounds of convection beginning tonight, will issue a Flood Watch across parts of southeast MO and southwest IL for Wednesday night and Thursday. A surface low will develop along the stationary front as an upper level trough deepens over the northern Plains. This low will deepen as it moves northeastward into northern IL by 18Z Thursday and drags a strong cold front southeastward through our forecast area on Thursday. Prefer the slower progression of the surface low and trailing cold front of the operational GFS and ECMWF models over the faster NAM model which appears to be an outlier. Temperatures are expected to fall on Thursday after the frontal passage due to strong cold air advection. A tight surface pressure gradient between the surface low and a strong 1045 mb surface ridge over the northern Plains will lead to strong gusty winds on Thursday. There may be a brief period of wintry precipitation on Thursday as the cold air filters into the region, but no accumulation is expected at this time as the colder and drier air shuts off the precipitation quickly. Most of the precipitation should shift east-southeast of our forecast area by Thursday evening. Unseasonably cold temperatures along with dry conditions can be expected beginning Thursday night and continuing into the weekend as the strong surface ridge moves eastward through the region. Another round of precipitation will begin Sunday and may continue into Tuesday as low- mid level warm air advection ramps up ahead of relatively weak shortwaves within nearly zonal upper level flow. Although temperatures will be gradually warming up, there may be at least a period of wintry precipitation across northeast MO and west central IL Sunday and Sunday night. The heavier precipitation amounts will likely occur across southeast MO and southwest IL where temperatures will likely be warm enough for just liquid rain. GKS && .AVIATION... (For the 00z TAFs through 00z Wednesday Evening) Issued at 545 PM CST Tue Feb 5 2019 IFR flight conditions will prevail across the entire region through the entire forecast period from a combination of low ceiling heights, and at times low visibilities from both precipitation and fog. A wave of rain will move across the area tonight that may have a bit of embedded thunder. I haven`t mentioned any thunder in the TAFS, but will amend as needed if there appears to be a direct terminal impact. KUIN will see predominately -FZRA. Will need to keep a close eye on KCOU - at this time the expectation is temps will stay above freezing with just -RA as the ptype, however should the winds become northwesterly and cool temps to at or below freezing then KCOU might see some -FZRA. For the St. Louis region, the precipitation will all be in the form of rain. The initial wave of precipitation will exit to the east of the terminals by 10-12z but another will be quick on its heels starting in central and northeast MO around 14z or so Wednesday morning. SPECIFICS FOR KSTL: IFR flight conditions will prevail through the entire forecast period from a combination of low ceiling heights, and at times low visibilities from both precipitation and fog. A wave of rain will move across the area tonight that may have a bit of embedded thunder. I haven`t mentioned any thunder in the TAF, but will amend as needed if there appears to be a direct terminal impact. The precipitation will all be in the form of rain. The initial wave of precipitation will exit to the east of the terminal by 10-11z but another will be quick on its heels starting around 15-16z or so Wednesday morning. Glass && .LSX WATCHES/WARNINGS/ADVISORIES... MO...Flood Watch from Wednesday evening through Thursday afternoon for Iron MO-Madison MO-Reynolds MO-Saint Francois MO-Sainte Genevieve MO. Winter Weather Advisory until noon CST Wednesday for Audrain MO- Boone MO-Knox MO-Lewis MO-Marion MO-Moniteau MO-Monroe MO- Ralls MO-Shelby MO. IL...Flood Watch from Wednesday evening through Thursday afternoon for Clinton IL-Fayette IL-Marion IL-Randolph IL-Washington IL. Winter Weather Advisory until noon CST Wednesday for Adams IL- Brown IL. && $$ WFO LSX
Area Forecast Discussion
National Weather Service Lubbock TX
522 PM CST Tue Feb 5 2019 .AVIATION... Low level flow remains backed from the east and southeast at KCDS this evening and raises distinct possibility for stratus developing overnight. We adjusted towards the latest HRRR trends, bringing low clouds and fog into KCDS a little before midnight. Will be adjusting further as necessary during the evening. Both KPVW and KLBB are expected to remain fairly well veered from the south- southwest overnight. A modest low level jet around 30 to 35 knots will develop, close to needing a LLWS wind shear remark. Also will monitor for this. Otherwise, mid and high cloud flow overhead will remain until gradually breaking up during the day Wednesday, timing of this is unclear, but afternoon should be sunnier than morning, and windier. RMcQueen && .PREV DISCUSSION... /issued 249 PM CST Tue Feb 5 2019/ DISCUSSION... Several things going on in this forecast in the next 48 hours, which was the main focus of the forecast package. Cloud cover has stuck around the forecast area today, both some low and high level clouds signaling moisture invading the region. Before one gets too excited, this moisture will be gone by tomorrow morning, but a few may get to enjoy its benefits tonight. A good fetch of moisture moved across the southeast half of our forecast area this morning, with another slug of moisture moving up out of the Trans-Pecos this afternoon. A swift shortwave tonight may give a quick shot of precip overnight, as models have been persistent on pushing showers across the FA after midnight. A strong 140KT jet max over the region may just give that extra umph to produce those showers. Still, rain totals are expected to be meager with only a few hundredths for most. The next order of business is tomorrow when the clouds and moisture move out and a trough starts to lift northeastward out of the Great Basin region. The approach of this system will induce rapid height falls kicking winds up across the entire region. These will be supported by a healthy jet max of 140-150KT, down to 85KT at 500, roughly 50-55 at 700 and a modest 35-45 at 850. Conditions will be decent for good mixing in the afternoon, so winds, especially on the Caprock were kicked into the Advisory category. So, a Wind Advisory does go into effect at noon tomorrow and lasts until 7 PM on Wednesday. Blowing dust is likely on the Caprock, especially near fields and construction sites, and driving on north-south oriented roads could be difficult at times. Finally, just as these winds are dying down, we`ll have a cold front that is dragged through on the backside of this trough. We have elected to go with the faster Euro solution on FROPA on Thursday morning, as this colder airmass fronts tend to move through quicker in the morning rather than stalling and then making a fast run in the afternoon. Therefore, highs on Thursday were dropped a few degrees to reflect the faster FROPA. Mainly stuck with the Blend past this, though did lower PoPs for the weekend into the slight chance as the chance PoPs still seemed a bit bullish attm. && .LUB WATCHES/WARNINGS/ADVISORIES... Wind Advisory from noon to 7 PM CST Wednesday for TXZ021>024- 027>030-033>035-039>041. && $$ 99/99/05
Area Forecast Discussion
National Weather Service San Francisco Bay Area
457 PM PST Tue Feb 5 2019 .SYNOPSIS...Rain showers and higher elevation snow showers will continue over Monterey and San Benito Counties this afternoon. Otherwise, dry weather conditions and cold overnight temperatures are likely midweek with unsettled weather likely to return late in the week. && of 01:38 PM PST Tuesday...After an exciting start to the day with low snow levels, hail and heavy rain weather conditions improved through the day. Snowfall reports puts a few inches across the North Bay and Santa Cruz Mountains and up to six inches in the East Bay Hills. Latest KMUX radar imagery shows scattered showers/snow showers pushing through Monterey and San Benito Counties. Snowfall in the Santa Lucias was about 4-5 inches this morning, but additional snow showers have likely added to that total. Based on radar and latest HRRR model output will keep Winter Weather Advisory in place through 4 PM for the higher elevations of the Santa Lucias/S Gabilan Range. Next weather impact and concern to the Bay Area will be the temperatures. Temperatures today are struggling to even reach 50 degrees in lower elevations. As precip continues to end from N to S and clouds clear from N to S overnight lows are going to be rather cold in some spots. Coldest temperatures tonight will be across the interior valleys and mountains - upper 20s to mid 30s. Urban areas will be warmer, but in the mid 30s to 40s. The cold weather will impact vulnerable populations and those without heat. The lingering dampness will exacerbate the issue making it feel colder. Black ice will also be a concern overnight as temperatures drop to freezing. Lastly, there is a chance for some patchy fog overnight with lingering low level moisture. If fog does form it could be freezing fog, especially in a place like Santa Rosa. A few lingering showers will be possible over the coastal waters and possibly skimming the coast (Big Sur) Wednesday, but most other areas will see an overall drying trend. Dry weather and below normal temperatures will continue Wednesday and Thursday. Medium range models show another round of precipitation approaching the Bay Area Thursday into Friday, but confidence wanes on timing. The latest NAM has really put on the brakes and in fact keeps most of the Bay Area dry through Friday afternoon. Not totally sold on the slower scenario and therefore will keep a chance over the North Bay Thursday night spreading south Friday. Snow levels will be about 3k so minor accumulations will be possible over the highest peaks - higher in the Santa Lucias. Unsettled weather, cooler temperatures and higher elevation snow will continue into the upcoming weekend. && .AVIATION...As of 4:57 PM PST Tuesday...VFR. Evening clearing, enhanced radiative cooling over recent snow cover resulting in NE-SE cold air drainage winds developing late tonight. A patch or two of freezing fog in the valleys is also possible tonight/early Wednesday morning; 00z KSTS taf VLIFR-LIFR in freezing fog Wednesday morning, VFR returning 17z at the latest. An amplifying, smaller scale 700 mb thermal trough will be moving southward over the coastal waters very late tonight, associated vorticity is mostly focused between 500 mb and 300 mb per NAM cross section thus the large displacement and disorganization should greatly limit areal shower development and coverage; based on model qpf maybe an isolated brief passing shower and/or virga develops nearest the coast very late tonight. Vicinity of KSFO...VFR. Onshore wind becoming light/variable by 12z Wednesday. Light E-NE Wednesday morning to early afternoon. NW wind near 10 knots mid to late Wednesday afternoon. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...VFR, onshore winds shifting to E-SE cold air drainage winds later this evening. SE wind 10-12 knots Salinas Valley by early Wednesday morning. Variable mid-late afternoon wind Wednesday, probably returning to E-SE Wednesday evening and night. && of 4:17 PM PST Tuesday...Moderate NW winds will bring hazardous conditions for small craft vessels through tonight across the waters, with isolated lower end gale force gusts possible through the day. For tomorrow, NW winds remain breezy across the outer waters through the afternoon but weaken for the inner waters. Moderate NW swell. && .MTR WATCHES/WARNINGS/ADVISORIES... .Tngt...SCA...Mry Bay until 3 AM SCA...Pt Arena to Pt Reyes 0-10 nm until 3 AM SCA...Pt Reyes to Pigeon Pt 0-10 nm until 3 AM SCA...Pigeon Pt to Pt Pinos 0-10 nm until 3 AM SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm until 3 AM SCA...Pt Arena to Pigeon Pt 10-60 nm SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm SCA...Rough Bar Advisory for SF Bar until 3 AM && $$ PUBLIC FORECAST: MM AVIATION: Canepa MARINE: DRP Visit us at Follow us on Facebook, Twitter, and YouTube at:
Area Forecast Discussion
National Weather Service Norman OK
550 PM CST Tue Feb 5 2019 .DISCUSSION... The February 6-7 00 UTC TAF discussion for KOKC, KOUN, KSPS, KLAW, KCSM, KWWR, and KPNC follows: && .AVIATION... Stratus and fog is expected to persist through the overnight hours across central and northern Oklahoma. These terminals will likely be near or below airport minimums with perhaps some improvement late morning (but likely still IFR). KSPS is currently expected to remain VFR, but there is a chance lower ceilings may even affect this terminal. Drizzle and fog will also be possible (with freezing fog and freezing drizzle across the north). Scattered showers may occur late tonight as well-- especially across the north. South to southwesterly winds above the frontal inversion will also result in low-level wind shear. Currently, winds are expected to change to southwest at ~1500-2000 ft AGL (30 to 35 knots). Some improvement to MVFR (through still below 2000 ft) may occur across far western Oklahoma (KCSM/KWWR). Scattered showers. Mahale && .PREV DISCUSSION... /issued 308 PM CST Tue Feb 5 2019/ DISCUSSION... Forecast challenge continues to be the motion of the warm front today and tomorrow, followed by a sweeping cold front late tomorrow night (with a potential for some wintry precipitation). Currently, fog is firmly set in across the northern half of Oklahoma. This is expected to continue to persist through the night, limiting any temperature changes in that area. Additionally, our northern two tiers of counties may see some freezing drizzle late tonight. A lot of uncertainty remains in the motion of the warm front. The GFS has significantly shifted from its northern solution to something closer to the middle while the NAM continues to keep the warm front further south. Trended close to the RAP for the first 12 hours stalling the front around I-40 (except for the western portion which continues to advance toward northwest Oklahoma) after that. Behind the warm front, increased winds and warmer temperatures (resulting in lower RH values) will present elevated fire weather concerns across our western counties Wednesday afternoon. Additionally, some precipitation could be supported south of the warm front (especially southeast Oklahoma) as moisture returns. Instability and shear will be enough to support thunderstorms, including some strong thunderstorms. As an upper system moves across the area, a strong cold front will sweep through Thursday night. Following closer to the NAM`s more aggressive timing of this front. This will bring better chances of precipitation out ahead of the front Wednesday night / Thursday morning. This system will leave us much colder Thursday. Temperatures will gradually warm back up into the weekend as we return to zonal flow. Precipitation chances will return early next week. Day && .PRELIMINARY POINT TEMPS/POPS... Oklahoma City OK 38 59 30 34 / 20 20 30 0 Hobart OK 46 74 31 38 / 10 10 10 0 Wichita Falls TX 59 76 42 45 / 30 30 30 0 Gage OK 34 67 21 32 / 10 0 0 0 Ponca City OK 31 42 24 29 / 20 30 30 10 Durant OK 67 71 48 53 / 50 70 90 20 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...Dense Fog Advisory until 9 AM CST Wednesday for OKZ009-014>030. Winter Weather Advisory until 9 AM CST Wednesday for OKZ004>008- 010>013. TX...None. && $$ 30/10/10
Area Forecast Discussion
National Weather Service Pueblo CO
837 PM MST Tue Feb 5 2019 .UPDATE... Issued at 826 PM MST Tue Feb 5 2019 Webcams, spotter reports and surface obs show dense fog becoming more widespread over the far southeast plains this evening, as colder air backs slowly west into CO. HRRR progs suggest vis will remain a quarter mile or less though the night, and will thus issue a dense fog advisory for the a few eastern plains zones near the KS border. && .SHORT TERM...(This evening through Wednesday) Issued at 306 PM MST Tue Feb 5 2019 Currently, water vapor imagery depicts a shortwave trough digging southeast across central California with southwest flow over Colorado. Associated cloud cover and snow showers have begun to increase in coverage over the Continental Divide. The high valleys and eastern Colorado plains are dry. West winds have slowly pushed east past the I-25 corridor, with gusts over 50 knots noted in Walsenburg, 40 knots in Trinidad, and 25-35 knots in Canon City and Colorado Springs. East of the westerly push, winds are still easterly, with low clouds present and slowly retreating near the Kansas border. Temperatures are in the 50s across the I-25 corridor, and 30s to 40s further east. Tonight, the push of gusty west winds and warm air is not expected to advance much further east as the sun sets and the low levels stabilize. Winds are forecast to begin to weaken shortly, becoming 5- 10 knots by 03Z across most of the plains. Temperatures this evening will drop into the 20s across the plains, and teens to 20s in the high valleys. Low clouds should stick around the far eastern plains through the evening, possibly pushing back west slightly. Tonight and tomorrow, the aforementioned shortwave trough and associated large scale lift will push east across the Great Basin and into Colorado by late Wednesday afternoon, spreading snow showers across the high terrain. Given the strong southwest flow associated with the system, the eastern San Juans are expected to see the greatest snow totals, with 8-14 inches in the forecast through tomorrow afternoon. The Winter Storm Warning remains in effect there from 00Z tonight through 00z Wednesday. The rest of the Continental Divide remains in a Winter Weather Advisory for the same period, with 5-9 inches of total snow accumulation expected during the period. The eastern mountains should see 2-5 inches through tomorrow afternoon, while the high valleys will generally see 1-3 inches. With strong jet winds overhead, gusts as high as 55 mph will be possible over the eastern San Juans and southern Sangres, and 45 mph over the central mountains, causing blowing snow and reduced visibilities. Over the southeast plains, the shortwave trough will help to deepen a surface low which will push east into southwest Kansas by late Wednesday afternoon. Southwest winds will increase across all of the plains in association with the tightening pressure gradient during the afternoon, and will be further augmented by deep vertical mixing and strong winds aloft. Winds could gust as high as 50 mph over Las Animas and Baca Counties tomorrow afternoon, with gusts to 40 mph possible elsewhere across the plains. The San Luis Valley is also expected to see winds to 40 mph mix to the surface. Daytime humidities are expected to stay above 20%, outside of critical concerns. By late tomorrow afternoon, a cold front and northerly winds in association with the upper level system will be pushing south across the eastern COlorado plains, just starting to enter northern portions of the forecast area. Isolated to scattered snow showers are expected to develop behind the cold front. Tomorrow, temperatures should climb into the mid to upper 50s across most of the plains as the cold front should not impact the forecast area until after daytime highs are reached. The high valleys are expected to see highs in the 20s to 30s. .LONG TERM...(Wednesday night through Tuesday) Issued at 306 PM MST Tue Feb 5 2019 An upper level disturbance will be moving over CO thru Wed evening, while a front is expected to move thru southeast CO during the evening. At this time, the front is forecast to back into Kiowa and Prowers counties late Wed afternoon, and should be entering northern El Paso county around 00Z Thu. Ahead of the front, gusty southwest to west winds are expected acrs the southeast plains, and then as the front passes the winds will be north to northeast and breezy. At this time, it looks like precip behind the front Wed night will mainly occur in areas north of highway 50, although the best chances should be over portions of Kiowa county, and mainly northern El Paso county. There is a chance that some freezing drizzle could occur over portions of Kiowa county, but at this time will lean more toward snow. Over northern El Paso county, snow accumulations look like they will be mainly under 2 inches. Along the CONTDVD, it still looks like there will be high chances for light additional snow accumulations in the evening, with chances then decreasing over the southwest mtns in the late night hours. With the upper trof moving east of CO in the late night hours, precip chances are expected to end acrs eastern areas, with just some light snow continuing along some of the CONTDVD. Another upper level trof move over CO on Thu, and keep the threat of some light snow along the CONTDVD. The GFS also has a threat of some light snow showers over El Paso and Teller counties in the afternoon. Temps Thu will be much colder, with highs only in the 20s in most lower elevation locations. Dry and warmer weather is then expected on Fri and Sat, although a few light snow showers my move into the mtns along the CONTDVD late on Sat. Sat night a disturbance moving over the state is expected to bring increasing chances for snow, and some light accumulations to the CONTDVD, along with breezy conditions over the mtns and the far southeast plains. This system quickly moves out of the area early Sun, with dry weather returning to all of southern CO. Another upper trof is expected to move acrs CO on Mon, bringing windy conditions and snow to the mtns and some of the high valleys. This is another fast moving system, and dry weather should return for Tue. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 306 PM MST Tue Feb 5 2019 A storm system approaching Colorado from the west will bring snow showers and reduced CIGs/VIS to the high terrain tonight through Thursday morning. At KALS, VFR conditions are forecast through Wednesday morning. Snow showers will develop near and over the terminal from late morning through early afternoon, reducing conditions to IFR or LIFR with lowering CIGs and VIS. Southwest winds will gust 25-35 knots from late morning through the afternoon At KCOS and KPUB, VFR conditions are expected for the next 24 hours. West winds will continue to gust to around 30 knots for the next few hours, weakening to 5-10 knots out of the south this evening. Winds will increase out of the southwest by tomorrow afternoon, gusting up to 30 knots. A cold front will advance south down the eastern Colorado plains tomorrow evening, causing winds to shift and become gusty out of the north at KCOS and KPUB after 00Z. CIGs will also lower behind the cold front, but should remain VFR to near MVFR. && .PUB WATCHES/WARNINGS/ADVISORIES... Dense Fog Advisory until 5 AM MST Wednesday for COZ095>099. Winter Weather Advisory until 5 PM MST Wednesday for COZ058-060- 066. Winter Storm Warning until 5 PM MST Wednesday for COZ068. && $$ UPDATE...PETERSEN SHORT TERM...LINE LONG TERM...28 AVIATION...LINE
Area Forecast Discussion
National Weather Service Blacksburg VA
640 PM EST Tue Feb 5 2019 .SYNOPSIS... A weak front will waver across the Appalachians and central Mid Atlantic region through midweek, bringing very warm temperatures but also some showers to the area. A cold front will then move through the region on Friday with another chance of showers and a surge of colder air moving in for the weekend. && .NEAR TERM /THROUGH WEDNESDAY/... As of 630 PM EST Tuesday... Latest update really only chose to push back the timing slightly for onset of precip moving into western areas per latest HRRR guidance. This should verify nicely as returns in western Greenbrier are limited and likely virga. Initial isolated precip that is expected tomorrow is still well off into central KY and southern OH. Will probably need to update temperatures again shortly to ascertain exactly how quickly the valleys will be radiating out in the coming hours but as of now, low temperature forecast seems on track. As of 130 PM EST Tuesday... Satellite imagery indicates clouds are a bit less widespread than expected and temperatures this afternoon are responding accordingly. Most locations east of the Blue Ridge are into the 70s early this afternoon with some maxes peaking near record territory, but where the clouds are hanging tough temperatures remain in the 50s. There may also be some patchy drizzle or sprinkles west of the Ridge especially along the hilltops. As low pressure moves into the Ohio valley it will push the diffuse frontal boundary back to the north a bit, keeping the Appalachians and central Mid Atlantic region mostly dry for the overnight period. However, we will stay to get into better isentropic lift toward morning which will bring us a steadily increasing chance of showers into Wednesday. The bulk of precipitation on Wednesday will be found west of the Blue Ridge and primarily up near the Interstate 64 corridor. Precipitation will decrease steadily further to the south and east with just some scattered afternoon showers for Southside and the Piedmont. Lows tonight will remain mild with readings remaining in the 40s. Wednesday also looks warm, though a bit cooler than today with highs generally mid/upper 60s east to upper 50s/lower 60s west. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/... As of 230 PM EST Tuesday... The frontal boundary will continue to lift northward as a warm front during Wednesday night into Thursday. As the front pushes northward, the Mid Atlantic will enter the warm sector of an organizing low pressure system over the central Plains. Although clouds may hold tough north of Interstate 64, some partial clearing could occur to the south by Thursday afternoon. With strong southwest flow aloft to provide warm air advection, high temperatures were steered toward the warmer MET guidance for Thursday. As a result, some locations in Southside Virginia and the North Carolina may flirt with 80 degrees. The climate section below addresses the records that will be in jeopardy during this unusual February warm spell. The aforementioned warm spell comes to a close by Friday as a potent cold front passes overhead. Model guidance is consistent that limited moisture will accompany the frontal passage, so only a chance of light showers has been advertised. Confidence is increasing for winds to reach or exceed advisory criteria behind the front during Friday afternoon into early Friday night. A large area of high pressure from western Canada exceeding 1040 mb combined with deepening low pressure over eastern Canada will bring pressure rises of about six millibars every six hours between 7 AM Friday morning and 1 AM Friday night. Low temperatures for Friday night were nudged downward to highlight the effects of cold air advection and clearing skies. && .LONG TERM /SATURDAY THROUGH TUESDAY/... As of 300 PM EST Tuesday... The upper level pattern becomes more zonal for this weekend, so this shot of cold air should not last too long. High pressure should shift offshore toward Sunday, which will turn the flow to the southwest. By Sunday night, the models diverge on how quickly an approaching frontal boundary arrives from the west. The GFS shows a slower solution than the ECMWF, and this discrepancy in timing may cause some precipitation type issues during early Monday morning. A residual wedge of high pressure east of the Blue Ridge will try to hold against increasing warm air advection and southwest flow aloft on Monday. Discrepancies in the model solutions over how strong this high will be along with its position leave this portion of the forecast in doubt on whether any light wintry mix may occur in the higher elevations. At this time, the forecast will favor mainly cold rain as there are concerns that the high may not end up in the best spot to really force the cold air southward. The frontal boundary will stall over central Virginia, which should set up a prolonged cloudy and wet period throughout Monday and Tuesday. && .AVIATION /23Z TUESDAY THROUGH SUNDAY/... As of 630 PM EST Tuesday... Conditions will be VFR to begin the TAF period. Prevailing flow will turn more southerly during the overnight hours, allowing for increased moisture to come into the region. This will result in sub-VFR conditions under low cigs and fog tonight, particularly in the mountain valley locations. As a cold front approaches from the west tonight into tomorrow, sub-VFR conditions will spread east of the Blue Ridge as well. Rain showers should arrive in the mountains tomorrow morning, beginning as isolated in nature before becoming more abundant leading into the afternoon hours. While showers making it into the piedmont tomorrow will be possible, the bulk of the precip will remain over the higher elevations. Winds will generally be light through the period with little impart to aircraft operations. Extended Aviation Discussion... Pattern remains unsettled into midweek with the next threat of rain and sub-VFR conditions being late Wednesday into Thursday. SCT MVFR rain and snow showers are possible on Friday, with with strong northwest winds behind the front Friday afternoon/night. Lower cigs appear to linger in them mountains into Saturday with VFR in the foothills/piedmont. && .CLIMATE... As of 415 AM EST Tuesday... Unseasonably warm temperatures may set a few records for the dates and record type below: Tuesday Feb 5th Record High Maxes: Bluefield 69 (2008) Roanoke 74 (2008) Danville 73 (2008) Lynchburg 75 (2008) Blacksburg 69 (2008) Wednesday Feb 6th Record Warm Lows: Bluefield 47 (2008) Roanoke 56 (2008) Danville 56 (2008) Lynchburg 56 (2008) Blacksburg 45 (2008) Thursday Feb 7th Record High Maxes: Bluefield 66 (2017) Roanoke 73 (2017) Danville 74 (2017) Lynchburg 72 (2017) Blacksburg 66 (2017) && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...MBS NEAR TERM...JR/MBS SHORT TERM...PW LONG TERM...PW AVIATION...JR/MBS CLIMATE...AL