Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/07/19

Area Forecast Discussion
National Weather Service La Crosse WI
530 PM CST Wed Feb 6 2019 .SHORT TERM...(This evening through Thursday) Issued at 250 PM CST Wed Feb 6 2019 A messy wintry mix of precipitation still looks to be on track to impact the area through the overnight hours. By mid-afternoon, some showery precipitation was beginning to move into far southwest portions of the forecast area as some weak shortwave energy was sliding through. Observations indicated a little bit of everything, with snow, sleet, and some freezing rain/drizzle; even a few lightning strikes were seen as some instability slid through. The mix will continue northeastward through this evening, with a dry punch aloft moving in behind it leading to a lack of ice in the cloud layer. Any precipitation should then transition to freezing drizzle, with soundings showing continued low level saturation overnight. Overall, looking 0.1 to 0.2" of ice accumulation. Much stronger energy will then move into the area by Thursday morning (around 12Z) as a long wave trough continues to slide eastward, with a surface low tracking northeastward through Missouri and Illinois. In addition to the stronger lift, much more moisture aloft will produce mainly snow across the area during the day on Thursday. Guidance has trended up with QPF during the day, with the 06.18Z RAP showing strong frontogenesis and some slantwise instability. Therefore, have upped snowfall amounts across the area, with 3 to 9 inches expected for most. The highest amounts will generally be north of Interstate 90 and east of the Mississippi River. A Winter Storm Warning has been issued for counties in this area, while the Winter Weather Advisory remains in effect elsewhere. .LONG TERM...(Thursday night through Wednesday) Issued at 250 PM CST Wed Feb 6 2019 Surface low lifts northeast into southern Ontario Canada Thursday evening. The 06.12z GFS/NAM continue to wrap snow across much of the forecast area Thursday evening...then begin to taper off to flurries after 06z Friday. The 06.12z GFS/NAM show tight pressure gradient across the forecast area through Thursday evening. With new fallen snow and potential for lighter fluffy snow...drifting and blowing snow can be expected in open areas...especially west of the Mississippi River. Colder airmass advects into the forecast area after 06z the 06.12z deterministic models suggest minus 20 to minus 25 degrees celsius at 925mb by 12z Friday. Combined with the wind...wind chill values will be in the minus 20 to minus 35 range late Thursday night into Saturday morning. High temperatures are expected to range in the single digits below and above zero Friday with low temperatures falling into the single digits to teens below zero Thursday night and Friday night. Temperatures warm slightly shortwave/surface ridge builds into the Great Lakes Region...and highs should climb into the teens across much of the forecast area. Main forecast concerns Saturday night through Wednesday are precipitation chances through the period. The 06.12z GFS/ECMWF/GEM are in good agreement digging upper level trough over western United States and moving upper level trough into the Upper Great Lakes Region through the period. Pieces of energy embedded in the southwesterly flow aloft/out ahead of the upper level trough will provide enough lift and forcing to produce snow across the southern portions of the forecast area late Saturday night into Sunday. Then...the deterministic 06.12z GFS/ECMWF/GEM lift upper level trough into the Central United States/Great Lakes Region Tuesday into Wednesday. This will allow for precipitation across the entire forecast area. However...confidence of timing of the upper level trough into the Great Lakes Region Tuesday into Wednesday remains low. For now...the higher likelihood of precipitation is expected to fall on Tuesday and Wednesday to be dry. Temperatures through the period should remain near or slightly below normal...mainly in the teens and 20s for high temperatures. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 530 PM CST Wed Feb 6 2019 Cigs: holding mostly IFR/MVFR through Thu evening, with improvement expected late Thu night into Fri morning as high pressure replaces current winter storm. WX/vsby: fzdz moves in tonight, lingering into early Thu morning. Brief period of sleet possible around 00z with convective band (maybe some T at KRST). FZDZ will swing over to snow around 12z or so, and then could be heavy at times from mid/late morning into the afternoon. Winds pick up as the day wears on, with the threat for BLSN at KRST before 00z. This would likely continue into the mid evening hours. The bulk of the accumulating snows look to be done by 00z Fri. Winds: pressure gradient tightens as winter storm pushes northeast of the area Thu afternoon. Northwest winds will increase and become gusty, persisting into the evening. Sustained +20 kts with gusts 30- 35 kts expected for KRST. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...Winter Weather Advisory until 6 PM CST Thursday for WIZ061. Winter Storm Warning from 6 PM this evening to midnight CST Thursday night for WIZ017-029-032>034-041>044. Winter Weather Advisory from 6 PM this evening to midnight CST Thursday night for WIZ053>055. MN...Winter Storm Warning from 6 PM this evening to midnight CST Thursday night for MNZ079-088. Winter Weather Advisory from 6 PM this evening to midnight CST Thursday night for MNZ086-087-094>096. IA...Winter Weather Advisory until 6 PM CST Thursday for IAZ008>011- 018-019-029-030. && $$ SHORT TERM...CA LONG TERM...DTJ AVIATION.....Rieck
Area Forecast Discussion
National Weather Service Caribou ME
1046 PM EST Wed Feb 6 2019 .SYNOPSIS... A weak weather disturbance will approach from the west tonight and dissipate to our south on Thursday. Low pressure will approach Thursday night and track northwest of our area Friday. && .NEAR TERM /THROUGH THURSDAY/... 1030 PM Update... The last 3 hr trends have shown temps holding the teens and 20s across the CWA and running higher than the previous forecast. The 00Z NAM and RAP keep temps up overnight and were matching well w/the latest conditions. Therefore, raised the overnight mins up a few degrees. Radar showed some enhanced returns moving across the region. Most of this was mid level clouds. However, looking at the obs across southern and sw areas, some sleet and freezing rain was falling out of a deck between 4-6k ft. This precip was light. Adjust the wx element to introduce some sleet across the southern areas overnight at the start of the precip and then some cooling should allow for precip to go to some light snow overnight. Also, backed up the timing of the precip and lowered QPF/SNOW amounts in the 00-06z time-frame. No changes made to the current Winter Weather Advisory. Previous Discussion... Hi cldnss is already sprdg across the Rgn, spcly across the N from QB prov as an initial s/wv with a first round of weak low to mid lvl warm/moisture advcn, mainly in the form of lgt sn which will ovrsprd the FA from the WSW late this eve and ovrngt. Ovrngt lows will likely occur during the mid eve hrs before temps become steady then begin to slowly rise durg the ovrngt hrs. Max snfl amts of 2 to 3 inches can be xpctd ovr W and interior SW ptns of the FA when sn tapers off by erly to mid morn Thu, with 1 to 2 inches ovr E Cntrl and interior Downeast areas and arnd an inch ovr the far N and Downeast coast. There is a chc that sn could mix with or even chgovr to lgt sleet ovr Downeast areas just prior to daybreak, but SREF precip type PoPs show an as the predominate precip type til about 7 am Thu. Aftwrds as the initial s/wv moves E of the FA Thu morn, it will remain cldy and dank as llvl E/ESE winds cont to bring llvl Atlc air into the Rgn between systems, with either very lgt mixed precip or lgt patchy fzdz ovr Cntrl/Nrn areas and lgt patchy dz alg the Downeast coast or patchy dz/fzdz for interior Downeast areas. Hi temps Thu will be milder than tdy by a few deg F. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... A large area of low pressure will be approaching Thursday night as a weak weather disturbance slides south of our region. Surface high pressure will move east across the Maritimes. The combination of the weak low to our south and the high to our east will hold cold air near the surface Thursday evening as the big low pulls warmer air northward aloft. As precipitation moves in late Thursday evening, temperatures aloft will be warm enough for sleet and freezing rain across most of the area. Freezing precipitation will be likely everywhere except coastal Downeast where temperatures should be warm enough for plain rain. Winter weather advisories will be issued for all inland areas Thursday evening By early Friday morning freezing rain will likely persist across the north while Downeast becomes warm enough for plain rain. Winter weather advisories will be issued for the freezing rain, overnight for all areas and into Friday morning for the north. Temperatures will then become warm enough for plain rain over the north by mid to late morning Friday as the big low tracks up to our northwest and warmer air works down to the surface. Rain will end around midday and some breaks of sunshine are likely Friday afternoon with a mild westerly breeze picking up. Very large and powerful low pressure will be tracking northeast through central Quebec Friday night as cold Arctic air circulates around the low and begins to surge in from the west. Steep lapse rates up to 8K ft combined with a secondary Arctic cold front may produce some gusty snow showers or even a localized snow squall Friday evening. The combination of the big low to our north and high pressure building to our southwest will bring very strong gusty westerly winds Friday night through Saturday. Some snow showers are possible over the far north late Friday night into Saturday morning. Drier air should then circulate in from the west Saturday afternoon bringing a trend toward clearer skies from south to north late Saturday afternoon. Winds Saturday may reach 20 to 30 mph gusting up to 45 mph. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... High pressure building south of the region will bring a mostly clear but windy and dry night Saturday night as the giant low lifts away into Labrador. Sunday will continue to be breezy as the high slide well south of our area. A small low will then approach late Sunday night into Monday morning bringing a chance for some light snow, mainly Downeast into Monday morning. High pressure will then follow bringing breezy and cold weather Monday night into Tuesday. The high will slide into the Maritimes, nearby to our north, Tuesday night into Wednesday bringing continued dry and more tranquil conditions. Another low may approach late Wednesday night into Thursday morning bringing a chance of snow, possibly again changing to mixed precipitation and rain as this low tracks up to our northwest. Clouds will then likely linger into Friday as an upper trough remains over the area. && .AVIATION /04Z THURSDAY THROUGH MONDAY/... NEAR TERM: VFR conditions will hold well into the eve as clgs lower, then conditions, spcly vsbys, lower to MVFR and IFR ovrngt and contg into erly Thu morn all TAF sites, as lgt sn ovrsprds the Rgn from the W. Conditions may briefly improve to low MVFR clgs mid to late Thu morn, then lower again Thu aftn as llvl warm advcn conts to slowly moisten the lower atmos. Patchy fzdz will be possible for spcly Nrn TAf sites by Thu aftn. SHORT TERM: Conditions will lower to IFR Thursday night and remain IFR to LIFR into Friday morning. Conditions will then improve to VFR Friday afternoon. VFR conditions Downeast and MVFR to VFR conditions over the north are expected Friday night into Saturday. VFR conditions are expected across the area Saturday night into Sunday. Very strong gusty west winds from Friday afternoon through Saturday night will likely result in turbulent conditions. Mainly VFR conditions are expected Saturday night through Sunday evening with a reduction to IFR conditions late Sunday night into Monday. Conditons should return to MVFR Sunday afternoon. && .MARINE... NEAR TERM: No hdlns anticipated for the near term. Kept close to a 12z WW3/NWPS guidance blend for fcst wv hts. SHORT TERM: Southerly winds are expected to increase to gale Thursday afternoon, then drop back to SCA Friday, before shifting to west and becoming a strong gale Friday afternoon through Saturday night. Cold air over the waters will likely result in freezing spray, possibly heavy, Saturday into Saturday night. Winds should drop back to SCA Sunday, then diminish below SCA Monday as high pressure builds in. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...Winter Weather Advisory from 8 PM Thursday to 10 AM EST Friday for MEZ001>004. Winter Weather Advisory from 8 PM Thursday to 8 AM EST Friday for MEZ005-006-010-011-031-032. Winter Weather Advisory from 8 PM Thursday to 6 AM EST Friday for MEZ015>017. MARINE...None. && $$ Near Term...Hewitt
Area Forecast Discussion
National Weather Service Des Moines IA
544 PM CST Wed Feb 6 2019 .SHORT TERM.../Tonight through Thursday/ Issued at 346 PM CST Wed Feb 6 2019 The weather will be quite changeable through the period with multiple elements of active weather. Our earlier burst of elevated instability producing dime to nickel hail in spots of central Iowa has weakened, but is still sufficient for lingering weak convection north. The H85 theta-e advection surge has recently blossomed additional weak sleet and/or freezing rain showers over northern Iowa with new lightning in spots as well. Farther south light freezing drizzle continues to expand along and just ahead of the weak KS/IA 925/850mb inverted trough. Pretty much expect persistent with this into the evening as the latest RAP shows continued saturation in that layer, but also with neutral to slightly subsident vertical motion and weak winds through 03z. Thus the current Winter Weather Advisory will remain in effect through the evening and into Thursday for most locations (see below). Our parent system is still well upstream, just moving through the Rockies, but should begin advancing through the High Plains overnight inducing yet another surge of warm/theta-e advection overnight. Corresponding 1-3km QG forcing will deepen that moisture eventually leading more toward freezing rain than freezing drizzle, with increasing frontogenesis toward daybreak as well. Deep forcing will be in place by 12z with a NW to SE changeover to snow in progress. There is fairly high confidence in a wintry mix north and icing south and east, including in the far southeast corner where lower static stability and proximity to the low level baroclinic zone may lead to higher QPF. Thus have added a small 12 hour Ice Storm Warning for three counties in the SE corner where accums may reach one to three tenths. Farther north and west snow is expected, but its efficiency (snow ratio) is somewhat uncertain as some models suggest spotty dendritic layer moisture, potentially leading to sleet or marginal crystals lowering amounts. There does seem to be a small three hour or so window where the dendritic growth zone moisture and omega phase however so still expecting three to five inch accumulations north. This will also be coincident with increasing winds as the system rapidly deepens moving from IL into the Great Lakes. Sustained speeds should reach 25 to 35 mph with wind gusts 40 mph plus at times. Thus blizzard potential comes into question. Have left Winter Weather Advisory in place for this element for now as confidence in snow type and wind gusts is marginal to go for a Blizzard Warning at this lead time, but the potential will certainly be highlighted in products and monitored further. With one to two inch accumulations down into central Iowa during this windy period, have ended the current advisory southward and extended until 00z. Also of note during the windy period Thu will be the potential tree and power line impacts where significant icing has already occurred. .LONG TERM.../Thursday night through Wednesday/ Issued at 346 PM CST Wed Feb 6 2019 Long term period begins Thursday evening with ongoing gusty winds and potential for blowing snow. Strong subsidence should bring most snowfall activity to an end, however with temp profiles falling through the dgz cannot rule out a few flurries/light snow showers. Did not add any mention of lingering -sn to the current forecast due to low confidence. Models today are a little more aggressive with the deepening surface low as it crosses the Great Lakes, now dropping it below 990mb. Tight pressure gradient on the backside of the low and persistent cold air advection maintains gusty northwest winds over the state through at least the evening hours. Threat of blowing snow transitions to another period of bitter cold wind chills as low temperatures fall below zero Thursday night, with wind chills dropping to between -20f to -40F. Wind chill headlines will be needed to highlight the threat, but opted not to issue just yet due to the complicated winter weather scenario in the short term. Much lighter winds but continued cold for Friday into Friday night as an impressive 1050mb high crosses the Upper Midwest. Highs on Friday will struggle just to get into single digits up north and teens south, then fall back below zero Friday night. Upper level ridge axis pushes through the central conus Saturday, setting up southwesterly flow aloft and lee side cyclogenesis in southeast CO. Low-level southerly flow/warm air advection will help temperatures rebound on Saturday. Models in fairly sound agreement with pushing a weak shortwave through the central Plains Saturday, however moisture is limited and likely fails to produce any sensible precip. That story changes as another shortwave trough quickly follows, this time with better moisture and strong mid-upper level QG support for lift. Temperatures profiles cold enough to generate light snow over much the area starting Saturday night. Precip continues into Sunday before upper level support gradually wanes. Not much change to the weather pattern into next week as the wave train stays active. Models continue to advertise a more robust system ejecting from the central Rockies Monday into Tuesday. Euro remains on the faster side of the guidance envelope than the GFS/GEFS mean, but similar in intensity and track. Potential exists for a decent shot of snow/blowing snow and impacts to travel over the region, however it is too far out to start diving into any specifics just yet. && .AVIATION.../For the 00Z TAFS through 00Z Thursday evening/ Issued at 544 PM CST Wed Feb 6 2019 Numerous considerations. IFR conditions to LIFR at times through 12z southeast; frozen mix at times with -fzra/-fzdz and low vsbys 1 to 3sm through 13z. As upper level system approaches; frozen mix changes back over to -sn and winds pick up behind the system 19-23z with possible blsn north. Significant icing possible at KOTM 06z to 15z with lighter icing most other sites. Confidence on ice totals still limited./rev && .DMX WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 6 PM CST Thursday for IAZ027-028- 033>039-044>050-057>062-070>073-081-082. Winter Weather Advisory until noon CST Thursday for IAZ074-075- 083>085-092>095. Winter Weather Advisory until midnight CST Thursday night for IAZ004>007-015>017-023>026. Ice Storm Warning from midnight tonight to noon CST Thursday for IAZ086-096-097. Winter Weather Advisory until midnight CST tonight for IAZ086- 096-097. && $$ SHORT TERM...Small LONG TERM...Martin AVIATION...REV
Area Forecast Discussion
National Weather Service Goodland KS
839 PM MST Wed Feb 6 2019 .UPDATE... Issued at 804 PM MST Wed Feb 6 2019 Just completed an update. Currently a narrow intense band of snow has developed over the eastern half of the forecast. This is a little east of what was earlier expected. High resolution, specifically the Arw, Rap, and Hrrr have picked up on this band nicely. This band matches up well with where the larger scale output has very strong frontogenesis collocated with theta-e lapse rates near or a little below zero. Fortunately this band is moving through rather quickly, and should be done/east of the area by late this evening. Also accumulating snow for the entire area should be done by 12z. As a result of this band affecting locations further east than expected, raised pops in the above mentioned area, increased qpf and snowfall amounts. The eastern portion of the area now is expected to receive 2 to almost 3 inches. With a large portion of the area having this light and fluffy snow on the ground, have inserted blowing snow into the forecast into the morning hours on Thursday. Cold temperatures and wind chill values still look on track. && .SHORT TERM...(This evening through Thursday night) Issued at 337 PM MST Wed Feb 6 2019 A Winter Weather Advisory remains in effect through 18Z Thursday. Remaining areas of freezing fog and freezing drizzle across the forecast area will diminish as the transition is made to all light snow this evening. There is a band of higher reflectivity returns showing up on the radar that is moving quickly eastward across the region late this afternoon and evening. Within this band of higher returns, snowfall rates will be briefly 1-2" per hour. Even with a brief period of moderate to heavy snowfall transitioning the area, total snowfall amounts should remain less than 3 inches. Snowfall is expected to diminish after midnight tonight as the system lifts quickly out of the southern plains early Thursday morning towards the Great Lakes by Thursday afternoon. Areas of flurries may remain through the day on Thursday with the cold air remaining firmly entrenched through Thursday night. Overnight lows Thursday night will be nearly identical to tonight, with the main difference being the winds. North winds of 20-30 mph tonight will continue into Friday morning. Combined with ambient air temperatures between -3 and +8 Thursday morning, Wind Chills between -15 and -25 are expected, which warrants the continuation of the Winter Weather Advisory through tonight and Thursday morning. With winds becoming light Thursday night, no wind chill advisory is anticipated with the similarly cold temperatures expected early Friday morning. .LONG TERM...(Friday through Wednesday) Issued at 314 PM MST Wed Feb 6 2019 The extended forecast will be active with a couple of shortwave troughs moving through the region. Friday morning, an upper level trough will extend from central Montana to the Great Lakes. Northwest flow aloft over the region will transition to southwest flow during the day as an upper level trough over the northwest deepens. A low forming on the lee side of the Rockies will extend into the Tri-State region Saturday night into Sunday. Still looking at relatively dry conditions, so no PoPs mentioned. A cold front will swing south through the area Sunday, dropping temperatures through the day. Expected high temperatures will be in the 20s and 30s. Another trough will move into the region on Monday. A chance of rain and snow is present Monday and Tuesday, though confidence any amounts and coverage is low at this time. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 414 PM MST Wed Feb 6 2019 Snow band with moderate to possibly heavy snow is beginning to work its way across the area. Behind this band the snow will let up and end with additional fog development. For Kgld, ifr/lifr conditions are expected through 02z with northeast winds of 15 knots with gusts around 23 knots. From 02z to 13z mvfr conditions will prevail north winds near 15 knots. However in the 04z to 06z time frame there will be a brief period lifr conditions with the north winds gusting to 23 knots. From 13z to the end of the period, vfr conditions and north winds around 17 knots are expected. For Kmck, mvfr conditions will quickly transition to ifr/lifr at 01z as the main snowband starts affecting the site. Those conditions along with northeast winds of 15 knots with gusts to near 23 knots will last until 06z. At 06z vfr conditions return and will last until the end of the period. From 06z to 08z the north winds near 16 knots with gusts to around 24 knots will continue. At 08z the north to northwest winds stop gusting with winds remain near 17 knots through the remainder of the period. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...Winter Weather Advisory until 11 AM MST /noon CST/ Thursday for KSZ001>004-013>016-027>029-041-042. CO...Winter Weather Advisory until 11 AM MST Thursday for COZ090>092. NE...Winter Weather Advisory until 11 AM MST /noon CST/ Thursday for NEZ079>081. && $$ UPDATE...BULLER SHORT TERM...LOCKHART LONG TERM...AW AVIATION...BULLER
Area Forecast Discussion...CORRECTED
National Weather Service Green Bay WI
934 PM CST Wed Feb 6 2019 CORRECTED HEADLINE CODING Updated aviation portion for 06Z TAF issuance and new information added to update section .UPDATE... Issued at 912 PM CST Wed Feb 6 2019 Was close to delaying the onset of the Winter Storm Warning until 6 am, but OSH and ISW have come in with FZRA and UP. So will stay the course with a 06Z start but rework the wording to highlight that we`ll only have light precipitation tonight and the worst conditions won`t occur until tomorrow. The 00Z models are coming in and still present somewhat mixed signals for the locations of the rain/snow line during the period of heavy precipitation tomorrow. The extended run of the HRRR at 00Z was similar to the 18Z GFS with 5-6 inches of snow at GRB. The 00Z NAM maintains more of a warm layer and a FZRA/IP sounding. We are dealing with very subtle differences in temperature, basically flirting with the level of predictability of the models, so it`s unlikely we will get this clearly resolved until we see how the precipitation behaves tomorrow morning. Edged snow totals N and W of GRB up a bit to try and sharpen the gradient in that area. Updated product suite will be out ASAP. UPDATE Issued at 618 PM CST Wed Feb 6 2019 The active pattern will continue as southwest flow sends another weather system into the area--this time a rapidly deepening cyclone that will race northeast from the Southern Plains on Thursday. Headlines for tonight are the first concern. A lead shortwave ejecting out of the Southwest U.S. upper trough was generating a band of mixed precipitation from near RST-MSN-RFD early this evening. That will continue lifting north during the evening-- crossing much of the area prior to the onset of the Winter Storm Warning. If the mixed precipitation transitions to mainly snow as it reaches the area, we`ll be okay because it would only generate an inch or two of snow as it is likely to remain narrow and progressive. But freezing precipitation would have a much greater impact and would probably necessitate starting the Warning immediately. We currently have flurries in GRB, and thermal profiles are cold enough for snow if we get deep/cold enough saturation-- which may occur in the band. Will be watching the evolution of precipitation type as the band shifts north, and may need to start the warning early if we end up with mainly FZRA/FZDZ. But would prefer not to do that because... There is likely to be a significant lull in the precipitation behind the lead band and the main surge of precipitation with the primary cyclone. Will consider delaying the onset of the warning until early tomorrow morning (~ 6am) if we don`t need it start it this evening. The final concern is precipitation type on Thursday. It`s always tough when one of these rapid deepeners comes racing up just to your east. Periods of lighter precipitation across most of the area may be FZRA/FZDZ due to saturation being of limited depth. But there will be a period mid-day when the intense forcing shifts through that the saturation will be deep enough for ice crystals everywhere. Precip type will then be modulated by the presence or lack of an above freezing layer aloft. The concern is a swath from ATW-GRB and just to the northwest. Model forecast soundings in this area are generally within a degree or so of having all snow during the period of max lift. If that were to occur. A burst of 4-8 inches of snow could occur within a few hours mid-day, before the precip changes to FZDZ as the upper dry slot surges across from the south. The 18Z GFS actually shows this, with BUFKit showing a COB-11 snowfall of 6.6 inches at GRB between 15Z and 21Z. Do not plan any major forecast changes at this time, but will issue an SPS detailing some of the high-impact aspects of the forecast during the next 24 hours. && .SHORT TERM...Tonight and Thursday Issued at 209 PM CST Wed Feb 6 2019 Despite the departure of the snow that fell overnight, cloudy skies continued to plague the forecast area this afternoon. There won`t be much of a respite from the active weather pattern as more precipitation is on the way later tonight and into Thursday as a low pressure system tracks to the southeast of the area. Precipitation will start later tonight as the region gets under the left exit region of a strong upper level jet with mid level isentropic lift as the warm air advection portion of the system approaches the western Great Lakes region. There will be issues saturating the atmosphere enough to create ice crystals, with quite a bit of freezing rain expected especially in the southern half of the forecast area. There will be a better chance for all snow across the north, however freezing rain will still be on the table according to model soundings. The brunt of the system will approach on Thursday as the low undergoes rapid cyclogenesis and deepens close to the rate of a "bomb". The area will be underneath the TROWAL on Thursday, with moderate to heavy precipitation rates during the late morning and afternoon hours. Precipitation type will be a mixed bag as dry air in the mid levels keeps freezing rain on the table for just about everywhere Thursday morning, with mainly snow across the north and west later Thursday afternoon when the main TROWAL arrives and the moisture becomes deep enough for mainly ice crystals to fall. Further east there will be issues getting all snow even Thursday afternoon as even when we saturate enough to get ice crystals, low level warm layers melt some of the snow to create sleet or melt it all the way for freezing rain. Overall this is a very complex forecast with many precipitation types expected from later tonight through the day on Thursday. Once the event is over snowfall totals are expected to range from 6 to 11 inches across north-central, with 4 to 8 inches across western portions of central, 3 to 5 across the rest of central and northeast, and up to 3 inches across east-central Wisconsin and the lake shore. In addition to the snow, ice accumulations could accumulate to around one quarter of an inch or more across east- central Wisconsin and the lake shore, with one to two tenths across central and northeast Wisconsin. Further north a few hundredths to up to a tenth of an inch is possible. Given this complex weather scenario will opt to issue a Winter Storm Warning instead of parsing out the different precipitation type scenarios with Ice Storm Warnings and Winter Storm Warnings. The thinking is if criteria is not reached on the snowfall front, it will be reached with the ice that is expected. Also if the storm track shifts it will make managing the headlines easier on subsequent shifts. If the forecast looks to be solid ice instead of snow, headlines can be adjusted for an Ice Storm Warning in subsequent forecasts. .LONG TERM...Thursday Night Through Wednesday Issued at 209 PM CST Wed Feb 6 2019 A lingering upper trough over the Great Lakes behind the departed storm will bring a bout of arctic air into WI for Friday through Monday. A new, strong upper trough is forecast to move inland into the western Great Lakes early next week and turn the mean flow to a southwest directions into WI, allowing for temperatures to moderate. There are timing issues with respect to the movement of this upper trough across the central CONUS during the Tue/Wed time frame with potential for heavy snow. Not as much cold air behind this system, thus temperatures to be at or slightly below normal mid-week. The strong surface low will continue to track northeast into southeast Canada with enough lingering lift and mid-level forcing from a cyclonic flow, to keep light snow in the forecast through Thursday evening. Additional snow accumulations to range from less than one-half inch over southern sections of the forecast area, to a couple of inches across far northeast WI. This would bring totals into the 1-3" range east-central WI, 7-11" northern WI. While synoptic snows end later Thursday evening, a wind shift to the west-northwest and strong CAA will lead to lake effect snow showers over north-central WI with up to an inch of accumulation over Vilas County. Min temperatures to drop into the zero to 5 below range central WI, around 5 above zero near Lake MI. Wind chills plummet into the -10 to -20 range with possible advisory conditions reached over central WI. The minor lake effect snow showers are expected to linger into Friday morning before starting to diminish as high pressure starts to build into the region from the Upper Midwest. Anticipate some sunshine to return on Friday (mainly in the afternoon), but with arctic air overhead, temperatures will be well-below normal. Look for readings to only reach around 5 above zero central WI, mainly 5 to 10 above zero eastern WI. This area of high pressure moves into the western Great Lakes Friday night, bringing mostly clear to partly cloudy skies, diminishing winds and very cold conditions. Near ideal radiational cooling conditions (plus the fresh snow) should allow temperatures to free-fall. Min temperatures to range from around 5 below zero near Lake MI, 15 to 20 below zero over the colder spots of north- central WI. As the surface high slides to our east on Saturday, winds will shift to the south and usher in some `warmer` air aloft (8H temperatures climb into the -14 to -7C range by 00Z Sunday). This could bring a general increase in clouds and keep max temperatures to only the 10 to 15 above zero range over most of northeast WI. Saturday night will remain quiet and not as cold with more cloud cover acting as a blanket. A weak shortwave trough located well to our south on Sunday could bring a small chance for light snow into southern parts of the forecast area. Otherwise, plenty of clouds are expected over the region with max temperatures on Sunday to range from the middle to upper teens north-central WI, upper teens to lower 20s elsewhere. This little system exits Sunday evening, allowing high pressure to move into the Great Lakes for Sunday night through Monday. This should leave skies generally partly cloudy with temperatures running 5 to 10 degrees below normal. This would bring max temperatures on Monday into the upper teens to lower 20s. Confidence remains very low with respect to the next potentially big winter storm to move across the central CONUS/Great Lakes toward the middle of next week. The models are different with the timing of the storm, different with the storm track and potentially different with precipitation type. We will need to watch this system closely in the coming days as heavy snow will fall somewhere over the Upper Midwest/western Great Lakes Tuesday/ Tuesday night. For now, have followed the consensus solution which runs chance pops from Monday night through Tuesday night and possible lake effect snow showers over Vilas County on Wednesday as winds shift to the northwest behind the storm. Below normal temperatures should persist through Wednesday. && .AVIATION...for 06Z TAF Issuance Issued at 912 PM CST Wed Feb 6 2019 Widespread low-end MVFR conditions prevailed across the area late Wednesday evening. Little change is anticipated overnight. A rapidly deepening cyclone will race northeast from the Southern Plains Thursday, bringing widespread wintry weather to the area and creating poor flying conditions. && .GRB WATCHES/WARNINGS/ADVISORIES... Winter Storm Warning from midnight tonight to midnight CST Thursday night for WIZ005-010>013-018>022-030-031-035>040-045- 048>050-073-074. && $$ UPDATE.........Skowronski SHORT TERM.....Kurimski LONG TERM......Kallas AVIATION.......Skowronski
Area Forecast Discussion
National Weather Service Indianapolis IN
1008 PM EST Wed Feb 6 2019 .UPDATE... The Near Term and Aviation sections have been updated below. && .SYNOPSIS... Issued at 238 PM EST Wed Feb 6 2019 A warm front is expected to linger across Central Indiana Tonight and early Thursday. This will be the focus for rain tonight and again on Thursday. This may result in flooding and a FLOOD WATCH remains in effect for much of Central Indiana. Low pressure is expected to push toward the Great Lakes on Thursday night from the southern plains. The low will drag a cold front across Central Indiana and bring more rain showers on Thursday afternoon...perhaps lingering into the evening. Colder and dry air is expected to arrive on Friday as Canadian high pressure builds across the Upper midwest and Ohio Valley. This will result in a dry but cold start to the weekend. More chances for precipitation will return on late Sunday and Monday as an area of low pressure is expected to push through the Ohio Valley. && .NEAR TERM /Tonight/... Issued at 1008 PM EST Wed Feb 6 2019 Adjustments to pops made per radar trends and HRRR progs, which appear to be tracking well with observed precipitation so far this evening. Will likely see a bit of a lull in some areas followed by another substantial batch of showers and perhaps an embedded storm or two later tonight. Dense fog will also be a concern at times, although may or may not be widespread enough to merit advisory. Dense fog has been mostly localized up to this point. Previous discussion follows. Issued at 238 PM EST Wed Feb 6 2019 Surface analysis early this afternoon shows a frontal boundary stretching from srn Illinois across central Indiana to nrn Ohio. Water vapor imagery continues to show a plume of tropical moisture steaming across Mexico...into Texas and then northeast to the Ohio Valley. A deeper trough aloft was found over the intermountain west. High pressure over the southeastern states was continuing to provide a warm and southerly flow of air to the Ohio Valley. Temperatures ranged from the upper 30s north to the lower 60s south as did the dew points across the area. The GFS and NAM again suggest another short wave aloft poised to push across Central Indiana this evening. As this upper wave forcing and support is found mainly across the southern parts of the forecast area where HRRR generates much of the precip. 300K GFS Isentropic surface shows very good up glide tonight with specific humidities over 6 g/kg...again very high for this time of year. Forecast soundings show deep moisture in place along with pwats over 1 inch. All of this along with the tropical plume aloft means that plentiful moisture will be available with the previously discussed short wave and forcing passing. Thus will trend pops at or above the forecast builder blends...particularly across the southern parts of the forecast area...trending lower at points north where forcing is less favorable. Given the expected clouds and precipitation will trend lows at or above the blends. && .SHORT TERM /Thursday through Saturday/... Issued at 238 PM EST Wed Feb 6 2019 The deep trough aloft over the western United States will progress eastward on Thursday...allowing an area of surface low pressure over the southern plains to push northeast along the warm frontal boundary toward the Great Lakes. The passing low pressure system will push a cold front across Indiana. Again plentiful moisture will remain in place ahead of the front. Forecast soundings show deep saturation once again with pwats over 1.4 inches. Thus will again use high pops on Thursday...and begin to taper things off on Thursday night as the frontal passage will be expected early in the evening....however the bulk of the precip should be over by 00Z as the models suggest dry air invading the column. Thus will trend pops lower rapidly with the onset of of dry air. Will stick close the forecast builder pops and temps on Thursday night. Strong high pressure is expected to build across Indiana on Friday and Saturday as ridging aloft strengthens across the plains states through the period. This will result in lee side subsidence across the Great lakes and Ohio valley on Friday through Saturday along with cold N-NW lower level flow. Thus will trend toward partly cloudy days and nights and trend temps at or below the forecast builder blends due to the colder air mass that is expected. && .LONG TERM /Saturday night through Wednesday/... Issued at 245 PM EST Wed Feb 6 2019 Models in good agreement that ridging will provide dry weather Saturday night. After that a western system will eject disturbances our way in southwest flow. Models as to be expected have issues agreeing on timing with these subtle waves. In addition, models are have temporal, spacial and strength issues with the evolution of the western system. So, confidence is low in any one solution, but overall it looks like an active period per the blend with potential for snow, rain and a mix at times starting Sunday. With confidence low, will accept the blend PoPs and temperatures. && .AVIATION /Discussion for the 07/03Z TAF Update/... Issued at 1008 PM EST Wed Feb 6 2019 Brief improvement in ceilings at some sites is not expected to last long with widespread IFR or worse ceilings upstream. Have made minor adjustments to some TAFs but the general TAFs remain valid. Previous discussion follows. Issued at 622 PM EST Wed Feb 6 2019 Poor flying conditions will continue through the majority of the period as widespread IFR or worse conditions persist. IFR conditions and MVFR visibilities will likely deteriorate again tonight, with LIFR conditions likely at all sites in rain showers and fog. Winds will be light and variable early in the period, gradually swinging around to the southeast, south, and then west as the period wears on. Speeds will strengthen tomorrow to around 10-15KT with gusts around 25-35KT. While thunder cannot be ruled out, it is too low probability at this time for an explicit mention. && .IND WATCHES/WARNINGS/ADVISORIES... Flood Watch through late Thursday night for INZ039>042-045>049- 051>057-060>065-067>072. && $$ SYNOPSIS...Puma NEAR TERM...Puma/Nield SHORT TERM...Puma LONG TERM...MK AVIATION...Nield
Area Forecast Discussion
National Weather Service Louisville KY
943 PM EST Wed Feb 6 2019 .Forecast Update... Issued at 930 PM EST Wed Feb 6 2019 Scattered to numerous showers, mostly light to briefly moderate at times continue over south-central IN and a good part of central KY. However, the main area of concern for heavy convective rains, and even occasionally strong to severe cells, has been across TN where a mesoscale boundary remains quasi-stationary and oriented roughly west to east, reinforced by the convective rainfall as it trains along and just north of the boundary. This has resulted in less rainfall late this afternoon and evening over much of central KY. However, latest radar trends show that some of the heavier rain over TN is now affecting our southern row or 2 of south-central KY counties, as the rain moves ENE. Latest high-res models including the HRRR suggest the boundary will remain over TN for the next few hours, which makes sense given no significant shortwave aloft to lift the boundary north into central KY overnight, and given the ongoing convective rains. Thus, significant rains for the next few hours will be confined to south- central KY where some training may occur, so will have to watch for significant ponding and localized flooding in this area. Models differ somewhat getting closer to Thu daybreak as to expected evolution. A couple high-res models lift the current convection into eastern TN and SE KY as it weakens, while others suggest some renewed activity coming into south-central KY later. There is also a sense that the western part of the boundary may start to lift NE into SW/central KY toward daybreak as the main wave aloft starts to eject well to our west. If this is the case, then slowly strengthening low-level winds from the S and SW would allow precip to begin redeveloping farther north into western and central KY and SW/south-central IN. Eventually, the boundary will continue to push north through the area on Thu as the main shortwave continues its approach and low-level winds back and strengthen. Temps overnight will remain nearly steady and could even rise a couple degrees. With weak surface winds and a very small surface temp-dewpoint spread, there could be at least patchy fog north of the boundary, so will add patchy fog to the forecast. && .Short Term...(This evening through Thursday Night) Issued at 230 PM EST Wed Feb 6 2019 Wet scenario for the short term, with multiple waves crossing the region. After this morning`s pass, another weaker wave should bring rains to the Wabash later this afternoon as well as reignite some precip along an effective boundary near the KY/TN border. The first system likely will bring a brief wave of rain across the northern two-thirds of the region tonight, whereas the southern focus will bring more prolonged rain chances. That boundary should move slowly north, possibly reaching the Pkwys in KY by daybreak Thursday. These fine scale motions are what will trigger our hydro issues, and it still is early to be certain about these. Thus the Flood Watch areawide still looks good. As for the severe threat this afternoon and tonight. The rains have helped to cool us down some/stabilize the area. Think to focus for any issues this evening will be closer to that effective boundary along our southern border. As the night continues, expect a narrow band where the shear and instability may be able to work together to produce a supercell or two, again over southern KY. Should the effective boundary move faster northward, that corridor would shift with it. As Thursday morning moves along, we should see coverage of showers diminish for most of the area, though southwest Indiana will have the best chance to keep in some rains through the morning hours. With a little more sunshine possible, expect us to tap into a tightening pressure gradient, and consequently stronger wind gusts. We could get near wind advisory criteria. MAV guidance gets in the low 20 knots for sustained winds, and this typically indicates potential to get up to 40 mph for gusts. Those strong south to southwest winds likely will help us break some records...see climate discussion below. That near record heat will set the stage for a line of strong to severe storms to roll through here later Thursday afternoon and evening. Latest hi-res guidance has trended just a tad slower for this line to move through the region...with it reaching the I-65 corridor in the 4-8 PM time frame and I-75 in the 6-10 PM time frame. At this point, feel the model soundings are underestimating the instability, showing temperatures at onset of precipitation in the mid 60s, when it probably will be higher. In similar recent setups though, that heating has helped to produce showers ahead of the main line that effectively rob the instability to feed that line. Will have to watch. CIPS analogs highlight an area along and west of I-65 with a chance for some severe reports, so will continue to highlight the threat. .Long Term...(Friday through Wednesday) Issued at 312 PM EST Wed Feb 6 2019 ...BRIEF BREAK IN THE WEATHER PATTERN FOR FRIDAY AND SATURDAY... ...ACTIVE WEATHER PATTERN EXPECTED FOR MUCH OF NEXT WEEK... ...ADDITIONAL RAINFALL THREATS MAY POSE ADDITIONAL FLOODING ISSUES... ============================== Friday through Saturday Night ============================== By Friday morning surface cold front is expected to be east of Kentucky with the back edge of the precipitation shield likely over far eastern KY. Temperatures will start off very cold with readings in the lower to middle 20s. Temperatures during the afternoon are not expected to move all that much with highs in the upper 20s over southern Indiana and in the 30-35 degree range over much of central Kentucky. Combination of clearing skies and light winds will allow a decent radiational cooling night for Friday night and Saturday morning. Temps Saturday morning look to cool into the 13-18 degree range region wide. With high pressure to the northeast of the region, we`ll see mainly an southeasterly flow develop. Some moderation in temps are likely with highs only warming into the 35- 40 degree range. Winds look to become more southerly Saturday night and Sunday morning as temps will only drop into the lower-mid 20s. ============================== Sunday through Wednesday ============================== The next weather system is poised to affect the region on Sunday. If precipitation develops quick enough, the northern edge of this precipitation could start off as a wintry mix before going over to rain. Rain is likely through the afternoon and into Sunday evening. Highs Sunday look to warm into the upper 30s to the lower 40s across southern IN and northern KY, with lower-mid 40s across southern KY. Lows Sunday night look to drop into the mid 30s in most locations. Some colder air may work its way down into our northern row of southern Indiana counties (per the GFS/FV3 solutions). However, the Euro has been trending warmer here, keeping wintry weather well north of the region. The Monday through Wednesday time frame will be quite unsettled. A robust southern Jet stream of Pacific origin will keep milder air and plenty of moisture flowing in across the southern Plains and into the Ohio Valley. Baroclinic zone looks to be just north of here with the Ohio Valley likely remaining on the warm side of the zone. Should this occur, we will be looking at additional periods of moderate to heavy rainfall which will only aggravate already saturated soils. This could very well lead to additional flooding and longer episodes of river flooding. Toward the end of the period (Tuesday night/Wednesday), a sharp upper trough looks to move through the region with a surface low cutting from the TX/OK panhandle northeastward into the Great Lakes. This would drag another cold front through the region late Tuesday with a cooler airmass working back into the region. Highs Monday look to range from the lower 40s over southern IN and northern KY. Mid upper 40s are likely over southern KY. Ahead of the cold front on Tuesday, we`ll warm back up into the lower-mid 50s over the north with upper 50s and possibly 60s over the south. Highs on Wednesday look to go back into the 40s. Overnight lows through the period will generally be in the 30s, with some 20s possible by Thursday morning. && .Aviation...(00Z TAF Issuance) Updated at 654 PM EST Wed Feb 6 2019 Messy weather will continue across the TAF sites through this period as a frontal boundary wavers across the region, and waves of low pressure ride along it. Expect intermittent showers through through the overnight, with the best chance at a T-storm down a BWG. Otherwise, precipitation should be pretty light at HNB/SDF/LEX. Ceilings are variable between MVFR and VFR, with occasional dips down to IFR possible. Not very high confidence in ceilings or visibility overall tonight. The frontal boundary will lift north of the area as a warm front into the day on Thursday, with gusty SSW winds taking hold and near record warmth. We`ll be mostly dry through the morning and the first part of the afternoon, although a few showers will still be around. A strong line of showers and some storms will then move through later Thursday afternoon into the evening, followed by a cold front. We should see a return to mostly high MVFR or VFR during the late morning and afternoon as the warm sector gets established. && .Climate... Issued at 200 PM EST Wed Feb 6 2019 Listed below are the record highs and forecasts for today and Thursday. Site 2/6 2/7 Rec. (Yr) Fore. Rec. (Yr) Fore. SDF 70 (2008) 65 69 (1925) 70 LEX 67 (1925) 64 67 (1925) 70 BWG 69 (2008*) 67 71 (1931) 73 FFT 68 (2008*) 65 69 (1925) 69 Listed below are the record warm lows and forecasts/obs for today and Thursday. The caveat with Thursday`s data is that the front will move through before midnight, likely pulling readings down below record levels. LEX stands the best chance to break their record, should the timing of the frontal passage slow down. Site 2/6 2/7 Rec. (Yr) Fore. Rec. (Yr) Fore. SDF 51 (1904) 51 55 (2017*) 39 LEX 47 (1904) 57 54 (2017) 44 BWG 55 (1938) 63 52 (2017*) 41 FFT 54 (1927) 53 56 (2017) 42 In addition to the warmth, a very moist airmass over the region likely will bring record rainfall. Below are the record rainfall amounts by date for Wed/Thu for each of our climate sites. Site 2/6 Record (Year) 2/7 Record (Year) SDF 2.21" (1883) 1.09" (1890) LEX 1.39" (2008) 1.30" (1890) BWG 1.30" (2008) 1.05" (1933) FFT 1.76" (1955) 0.87" (2018) && .LMK WATCHES/WARNINGS/ADVISORIES... IN...Flood Watch through late Thursday night for INZ076>079-083-084- 089>092. KY...Flood Watch through late Thursday night for KYZ023>043-045>049- 053>057-061>067-070>078-081-082. && $$ Update..,,,,.TWF Short Term..,RJS Long Term..,.MJ Aviation..,,.BJS Climate.,,,..RJS
Area Forecast Discussion...UPDATED
National Weather Service Mobile AL
558 PM CST Wed Feb 6 2019 .DISCUSSION...Updated for latest aviation discussion below. && .AVIATION... 00Z issuance...IFR to LIFR conditions are expected to develop shortly after 07.01z and continue through 07.15z followed by IFR to MVFR conditions through 08.00z. Visibilities and ceilings will begin to deteriorate shortly after sunset and continue through mid morning gradually improving through late afternoon. Winds will be southerly at 5 to 10 knots through 08.00z. 32/ee /7 && .PREV DISCUSSION... /issued 336 PM CST Wed Feb 6 2019/ NEAR TERM /Now Through Thursday/....06.12Z upper air analysis shows a northeast to southwest oriented ridge axis from the Mid- Atlantic to the Gulf, while a sharpening upper trof was positioned over the Intermountain West. At the surface, synoptic scale high was centered off the US east coast. West of the high, a warm, moist southerly flow is forecast to persist going into Thursday. For tonight, a persistence type approach will be taken which favors another round a dense fog formation over much of the area. SREF probabilities of visibility lowering to a mile or less is 60 to 90% over the southern zones, focused along the coastal counties. The high res. RAP and NAM12 favor the development of extensive fog, visibility lowering to at or less than a quarter mile along and southeast of I-65. The HRRR also shows dense fog, but not with the widespread coverage as the NAM12 and RAP. Considering the output from 3 out 4 guidance fields, A dense fog advisory will be issued for tonight, which will carry over into mid to late Thursday AM. As far as temperatures, may see warm low temperatures tonight near record levels over several areas. Thursday, strengthening warm air advection ahead of a strong cold front diving into the Lower MS River Valley late in the day, supports very un-February like temperatures with near record warmth being advertised with highs lifting up into the upper 70s to perhaps the lower 80s. A small chance of showers over the western zones Thursday. Here`s a sampling of the latest records (Lows/Highs) for Thursday that could be matched or broken. Mobile- 65/78, Pensacola - 66/79, Crestview - 58/80 Evergreen - 59/77, Waynesboro - 63/82, /10 SHORT TERM /Thursday night Through Saturday night/...A vigorous shortwave trough currently moving through the longwave trough over the western states will propagate east and then northeastward driving a cold front across the region Thursday night. Main dynamics and upper forcing with this system will be displaced well to the North of our area. Expect only some light shower activity along and behind the front as it sweeps southeastward into Southeast Mississippi and Southwest Alabama Thursday evening and east of Northwest Florida and South Central Alabama after midnight. Surface high pressure over the Eastern Gulf will keep a warm moist southerly surface flow going ahead of the front allowing for fog to spread inland during the evening hours Thursday night and scour out in the wake of the front. Behind the front, Northerly surface winds will advect in drier air scattering out the low level moisture and cloud cover but mid and high level cloud cover will continue to advect over the area through Saturday. Surface winds are modeled to veer to a east to southeasterly direction Saturday night as surface high pressure to the north shifts east to the eastern seaboard. Overnight radiational cooling inland will probably assist in keeping surface winds from a Northeast to Easterly direction, but the flow above the boundary layer will likely become southeasterly creating isentropic ascent and the gradual saturation of the low levels resulting in some overnight fog development. Overnight lows Thursday night will be greatly dependent on the passage of the cold front. This forecast package has Thursday night minimum temperatures ranging from low to mid 40s over Wayne and Choctaw counties to mid to upper 50s over South Central Alabama and Northwest Florida. Daytime highs Friday and Saturday will trend cooler than climatological normals for a change: ranging from the low to mid 50s west of the I-65 corridor and upper 50s to low 60s east. Lows Friday night dip into the mid 30s inland to low to mid 40s along the coast and upper 30s to lower 40s over interior locations to near 50 along the immediate coastline Saturday night. /08 LONG TERM /Sunday Through Wednesday/...A southerly return flow develops Sunday as a broad area of surface high pressure shifts eastward over the Western Atlantic. As a result, temperatures and moisture begin to climb and overnight-morning fog returns to the region. A southwesterly flow is expected to prevail aloft creating the possibility of passing shortwave troughs triggering some isolated to scattered shower activity in the warm sector overlying the region Sunday night through Tuesday. Another cold front is progged to move across the region Tuesday night bringing increased shower activity with it and gradual drying and cooling in its wake. /08 MARINE...Main hazards in the near term will be low visibility in dense fog. A warm, southerly, moist flow (dewpoints in the mid to perhaps upper 60s), atop cooler bay and inland waterways (where water temperatures range in the mid to upper 50s) support a pattern for persistent advective type fog in the near term. A strong cold front makes passage late Thursday night to around day-break Friday which scours out fog and moisture. In the wake of the frontal passage, small craft advisories will likely be required due to an evolving strong offshore flow and building seas to close out the week. /10 && .MOB WATCHES/WARNINGS/ADVISORIES... AL...Dense Fog Advisory until 10 AM CST Thursday for ALZ056-059-060- 261>266. FL...Dense Fog Advisory until 10 AM CST Thursday for FLZ201>206. MS...Dense Fog Advisory until 10 AM CST Thursday for MSZ078-079. GM...Dense Fog Advisory until noon CST Thursday for GMZ630>636-650- 655. && $$ This product is also available on the web at:
National Weather Service Charleston WV
701 PM EST Wed Feb 6 2019 .SYNOPSIS... Periods of rain, mainly across southern sections through early Thursday morning. Strong cold front Thursday night. Cold high pressure this weekend. && .NEAR TERM /THROUGH THURSDAY/... As of 450 PM Wednesday... Adjusted PoPs and Weather grids per latest radar imagery trends. This resulted in lowering PoPs areawide, as rain showers exit east, faster than anticipated. Also, went more deterministic across northern portions of southeast Ohio and WV, cutting PoPs below 15 percent through the overnight hours. Any pcpn there should be drizzle if anything. Additional periods of rain are still expected across northeast KY, southwest VA and southern half of WV into the predawn hours Thursday. Expanded areas of dense fog west from the northeast mountains, west and south, to cover northern portions of southeast OH and West Virginia through early Thursday morning. Latest HRRR model is in agreement with this thinking. Hourly temperatures were revised and matched with past observations resulting in couple degrees lower for High temperatures this afternoon. Rest of forecast remains on track. As of 135 PM Wednesday... Impressive low level theta e axis embedded within a belt of stout low level moisture advection continuing to give southeast OH moderate to heavy rain. Amounts to 2 inches are now being reported in spots with several flooded roads. Models agree on pushing this axis southeast as the surface wave departs this afternoon, with a bit of a progressive nature to it. This should keep rainfall amounts closer to 1 inch rather than the 2+ that has been observed across southeast OH. This continues this evening with the boundary draped across far southern zones. This would allow for a much needed lull across southeast OH, northeast KY, and northern/western half of WV. The sharp low level theta e boundary along with some weak instability aloft keeps some thunder mention as it moves through the area with some beefy rainfall rates for this time of year. The axis stays draped in the vicinity of our southwest VA counties overnight with rounds of moderate to occasionally heavy rain pegged by the models. This is where QPF picks up again, where up to 2 inches may fall. I toyed with adding a few counties down that way to the watch, but given the uncertainty on where this axis ultimately ends up, elected to hand off to the evening shift to monitor. Elsewhere, low clouds and areas of dense fog will develop overnight. Forcing for ascent weakens considerably Thursday morning, as the boundary lifts back north through the area in response to strengthening low pressure traversing through the mid and upper MS Valley. As such expect coverage of showers to stay mainly confined to western zones in the morning. Low clouds and fog will lift as this pushes north with southerly winds picking up in the afternoon. It still appears at least some sun will be realized across a good portion of the area, especially east of the OH River. This will boost afternoon temperatures into record territory for the day. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/... As of 240 PM Wednesday... As the cold front moves through, one of the questions in the forecast process is the potential for thunder with the associated line of showers. Took a conservative approach with this with, but even though there is no thunder in the forecast, some isolated embedded lightning is not out of the question. Otherwise, the main threat continues to be any additional rain, so will need to assess the state of the ground/waterways prior to the convective line. This should largely be the last of the significant rainfall with this long duration event that has begun today before this issuance, and has a chance of becoming snow showers with the dramatic temperature falls back into the 30s/upper 20s. No accumulations expected as this follows a typical case here with the colder air chasing the moisture out of the CWA. Front end of the weekend will be cold, back in a more winter-like airmass, but dry with high pressure building into the southern Great Lakes. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... As of 240 PM Wednesday... Zonal flow aloft turns southwesterly, reverting to another wet pattern for the end of the weekend/beginning of the work week. Another developing baroclinic boundary will set up in the vicinity of the Ohio Valley, with indications of more low level moisture transport into that area. Could see waves of rain through mid week until the next upper low/surface low combo clears out the airmass once again at the end of the extended. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... As of 155 PM Wednesday... Radar images indicate most of the rain showers have exited east of the mountains early this evening. Surface observations indicate IFR/LIFR conditions across northwest sections of our CWA, affecting PKB this evening. Latest high resolution models suggest saturated layer from SFC through few hundred feet AGL, will spread east to affect CKB and EKN overnight. Despite of abundant cloud cover expected, areas of IFR/LIFR conditions under dense fog are likely over these areas as well. This post- rain IFR/LIFR conditions should reach CRW by 07Z, then lifting temporarily to low MVFR after 09Z tonight. Another period of light to moderate rain will move from the southwest into our CWA by 03Z. Expect MVFR/IFR conditions along the eastern mountains to prevail through at least 12Z Thursday. This activity is associated with a second wave of energy passing over a nearly stationary sfc boundary evident in low layered theta-e gradient. Expect this feature to serve as the focus of pcpn during the overnight hours into early Thursday morning. Tonight could be a prolong period of IFR conditions areawide, with few exceptions. Ceilings and visibility will begin to improve into MVFR to VFR conditions by mid morning Thursday. Calm to light and variable winds will prevail through at least 13Z Thursday. Models suggest H850 winds become southwest, increasing to 40-50 knots by 18Z Thursday. Expect some of these winds to mix down under rain showers to produce gusty winds at most places, more likely over elevations higher than 3000 feet. Terminals should experience prevailing 5 to 12 kts gusting 20 to 25 kts mainly during the afternoon and higher elevations. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z FRIDAY... FORECAST CONFIDENCE: High. ALTERNATE SCENARIOS: Areas of IFR or worst under dense fog could vary across the northern sections overnight. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 22 23 00 01 02 03 04 05 06 07 08 09 EST 1HRLY 17 18 19 20 21 22 23 00 01 02 03 04 CRW CONSISTENCY H H H H H H H H H L L L HTS CONSISTENCY H H H H H H H M H H H L BKW CONSISTENCY H H M H L M M M M L H H EKN CONSISTENCY H H H H M H H L L M M M PKB CONSISTENCY L M H H H M L M M M M M CKB CONSISTENCY H H H M H M M M L L M M AFTER 00Z FRIDAY... Periods of IFR in periods of rain Thursday night. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...Flood Watch through Thursday afternoon for WVZ005>011-013>020- 024>026-029. OH...Flood Watch through Thursday afternoon for OHZ066-067-075-076- 083>087. KY...Flood Watch through Thursday afternoon for KYZ101>103-105. VA...None. && $$ SYNOPSIS...26/30 NEAR TERM...ARJ/30 SHORT TERM...26 LONG TERM...26 AVIATION...ARJ
Area Forecast Discussion
National Weather Service Springfield MO
933 PM CST Wed Feb 6 2019 .MESOSCALE DISCUSSION... A stationary front is currently (0330Z) lined up roughly from Jane to Ozark, to Montauk State Park. South of this line, instability continues to increase with additional moisture flux into the lower trop. RAP13, NAM, and HRRR low level cape (ML-3km) fields suggest values increasing between 30 and 90 j/kg through the overnight hours within a highly sheared airmass across southern Missouri. This region will experience the better chances of organized storm development capable of producing tornadoes, large hail, and damaging wind gusts. There is also a large hail risk north of the front where cape rooted from elevated parcels will exceed 1000 j/kg through the night. High resolution CAMS show deep convection increasing through the night across much of southern Missouri. This will also pose a flash flood risk as one state route low water crossing has been barricaded by MODOT in northern Wright County (Elk Creek at Highway Z). && .SHORT TERM...(This evening through Thursday) Issued at 158 PM CST Wed Feb 6 2019 A strong frontal boundary remains draped from southwest to northeast from northwestern Arkansas to around the Dent/Shannon County line. South of the front, temperatures are in the upper 50s and lower 60s. North of the front, temperatures are much colder with readings still in the upper 20s from around Pittsburg, Kansas to Warsaw, Missouri. Showers continue this afternoon mainly south of the front in the warm sector, however areas of freezing drizzle have persisted north of the freezing line. Areas of dense fog also persist north of the front. As we head into this evening, that warm front will creep north as strong height falls begin to overspread the region. Short term and hi res models are still struggling with the extent that the front shifts north. Current thinking is it will nudge as far north as a Cassville to Marshfield to Rolla line late this evening. Meanwhile, surface low pressure will continue to deepen and slowly swing northeast along this front. The potential for dense fog will remain tonight to the north of the front. Of greater concern will be significant wintry weather along with the threat for severe storms and flooding. Starting with "warm" side of the storm, we continue to believe that all modes of severe weather will be possible from this evening into early Thursday morning. Supercell and line segment convective modes will be possible throughout the evening with a greater likelihood for line segments as the main forcing gets into the area late tonight. Enough MLCAPE (500-900 J/kg), deep layer shear, and low level background helicity will exist for a supercell tornado threat. Storms near the front will have to be watched closely as they will tend to track right along this boundary (increasing the potential for enhanced vorticity ingestion). The RAP model has also nudged up significant tornado values over the last few runs, thus we are going to maintain the threat for a strong tornado or two. We have also expanded the potential for large hail to include areas north of the surface front as MUCAPE values will be sufficient to support quarter-sized hail. Any supercells in the warm sector would have the potential to produce hail up to the size of ping pong balls. As for line segments, low-level shear vectors will favor mesovortex tornadoes with anything bowing towards the east or northeast. Additionally, damaging straight-line wind gusts will be possible with any bowing line segments and mesovortices. We also remain concerned with the flooding potential of creeks, streams, and low water crossings across mainly southern Missouri. Many locations have already seen rainfall amounts of 0.50" to 1.25". Additional rainfall amounts into early Thursday will likely be in the 1.00" to 2.00" range. Moving to the winter side of this storm system, short term models have continued their trend of increasing QPF as the main upper level support approaches. A large amount of this QPF appears to be convective in nature. When it comes to precipitation type, convective precipitation really throws a wrench into the forecast. We believe that a combination of freezing rain and thunderstorms producing sleet will be the main precipitation types as we get into tonight. This will especially be true north of a Joplin to Stockton to Versailles line where an Ice Storm Warning is in effect. Expected additional ice amounts from 0.20" to 0.40" can be expected. Additionally, sleet amounts of 0.10" to 0.25" are expected. Given the expected thunderstorms, some localized areas may easily exceed 0.50" of sleet. With northwest winds increasing late tonight and Thursday morning, there is some concern for isolated power outages. As that low begins to swing through the Ozarks, it will drag that cold front southeast through the Missouri Ozarks late tonight and Thursday morning. This should result in a transition to a light wintry mix across much of the remainder of central and southwestern Missouri. We have therefore posted a Winter Weather Advisory for this area with that advisory starting at 3 AM. Both the advisory and warning are set to expire at noon on Thursday as most precipitation should be wrapping up. Once precipitation ends on Thursday, the main story then becomes cold conditions. Temperatures over most areas will either be steady or will slowly fall with high temperatures occurring in the morning. Wind chills will actually dip into the single digits across western Missouri and southeastern Kansas in the afternoon. .LONG TERM...(Thursday Night through Wednesday) Issued at 158 PM CST Wed Feb 6 2019 A cold Canadian airmass will be in the process of oozing across the plains and into the Ozarks Thursday night and into Friday. Morning lows Friday will bottom out in the upper single digits to middle teens with wind chills falling from the zero mark to 10 below zero. Clearing skies will also help allow for radiational cooling to take place thus temperatures were knocked down a degree or two from what models had given to start with. Another item that could make for cooler temperatures will be any ice, snow or sleet that accumulated through Thursday evening across the region. The cold air will continue to make its way into the region through the day Friday. This will keep high temperatures in the lower 20s across central Missouri to around the freezing mark across far southern Missouri. Temperatures will remain cold into Saturday morning with winds picking up somewhat which will keep morning wind chills in the zero to 10 below range once again. By Sunday morning, another round of precipitation will begin to spread over the region but may be shunted south of the region briefly early Monday morning. Models are having a hard time with the storm system for the early to middle portion of next week. Suffice it to say that the active weather pattern will continue next week with periods of day time rain and night time wintry weather through the middle of next week. Depending on the track and strength of the systems for next week, we could see another round of what we have currently. The potential for severe weather and wintry weather is again a possibility. Welcome to weather in the Ozarks. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 554 PM CST Wed Feb 6 2019 A very complex weather pattern over the region will bring multiple flight concerns for aviators flying into the Ozarks over the next 24 hours. Ceilings and visibilities will be predominantly low end MVFR to IFR. A few periods of improved conditions will occur but will be short lived. Weather ranging from thunderstorms with hail to dense fog to freezing rain will make the flight conditions difficult over the area. A cold front will begin to clear out the region, but not until after 18z Thursday. Additionally, a very strong low level jet will bring low level wind shear and gusty surface winds to the area after sunrise Thursday as well. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...Flood Watch through Thursday afternoon for MOZ082-083-090>098- 101>106. Dense Fog Advisory until 3 AM CST Thursday for MOZ057-058- 069>071-079>083-088>098-101>106. Winter Weather Advisory from 3 AM to noon CST Thursday for MOZ057-058-069>071-079>081-089>095-101>103. Ice Storm Warning until noon CST Thursday for MOZ055-056-066>068- 077-078-088. KS...Dense Fog Advisory until 3 AM CST Thursday for KSZ101. Ice Storm Warning until noon CST Thursday for KSZ073-097-101. && $$ MESOSCALE...Cramer SHORT TERM...Schaumann LONG TERM...Hatch AVIATION...Hatch
Area Forecast Discussion
National Weather Service San Angelo TX
552 PM CST Wed Feb 6 2019 .AVIATION... /00Z TAFS/ Currently, we have VFR conditions across the area with gusty southwest winds. Scattered showers and thunderstorms are expected to move into the area within the next few hours, continuing through midnight tonight before a Pacific cold front moves through, pushing the activity east and out of the area by 09Z or 10Z. Will continue to carry either VCTS or TEMPO groups for thunderstorms tonight. West to northwest winds will follow the front, increasing to 15 to 25 knots by mid morning Thursday. A second front will move south through the area tomorrow, but likely only make it through the KABI area before the end of this TAF forecast. 20 && .PREV DISCUSSION... /issued 302 PM CST Wed Feb 6 2019/ SHORT TERM... (Tonight through Friday) A spring-like day continues across West Central Texas this afternoon, with temperatures in the 70s and dewpoints in the 50s and 60s for most locations. A Pacific front is still set to move into the area this evening with showers and storms developing ahead of the boundary. Latest HRRR and TTU WRF show convection developing mainly east of an Abilene to San Angelo line by mid evening, and then spreading east and out of the Heartland and Hill Country before sunrise. Will continue the highest PoPs to the east with decreasing chances across the western Concho Valley and Big Country. Drier and cooler conditions for Thursday for most areas, with highs mainly in the 50s. The arctic front that has been sitting across the Red River today will surge south as well, reaching the northern Big Country before noon and moving across the rest of the area by late afternoon. This will bring the coldest air mass to the area, with lows dropping well into the 20s for most of West Central Texas by Friday morning. Wind chills will be even colder, dropping into the teens. Low level moisture will be scarce, but models suggest mid level moisture will rapidly increase as overrunning begins to become established. GFS and ECMWF show a little precip developing across the southeast counties, east of a Brownwood to Brady to Junction line. Model soundings actually suggest that snow will be developing aloft and melting as it reached the ground, perhaps even reaching the ground in those areas where the precip is heavy enough to wet bulb temperatures down far enough. Suspect that the rain will be light enough to keep most areas as rain, but will add a mention of rain/snow mix as a possibility. LONG TERM... (Friday night through Wednesday) A few sprinkles possible Friday Brown and Saba counties. Confidence is low, however, as most of the models indicate dry air in the low levels and most/if any precipitation would evaporate before hitting the ground. A few flurries could also mix in as temperatures aloft will be below freezing. There is a chance of showers Saturday night into Tuesday Monday as surface high pressure moves east, allowing low and mid level moisture to return to the region. Rainfall amounts will be generally light each day. A warming trend will continue with highs in the lower to mid 40s Saturday to upper 50s/lower 60s Sunday and mid/upper 60s Monday. Rain chances end Tuesday night as an upper through/low moves across Oklahoma and Kansas, bringing drier and more stable air into West Central Texas. It will be slightly cooler with highs in the lower 60s. && .PRELIMINARY POINT TEMPS/POPS... Abilene 47 55 24 39 / 50 0 0 5 San Angelo 48 60 26 39 / 40 0 0 10 Junction 52 65 30 39 / 50 10 0 30 Brownwood 50 61 27 39 / 70 5 0 20 Sweetwater 44 56 24 39 / 30 0 0 5 Ozona 46 60 29 41 / 30 0 0 10 && .SJT WATCHES/WARNINGS/ADVISORIES... None. && $$
Area Forecast Discussion
National Weather Service Tulsa OK
955 PM CST Wed Feb 6 2019 .DISCUSSION... Widespread convection continues from the Tulsa area to the north at this time, with a few cells producing small hail and wind gusts to around 40 mph. Freezing temperatures likely resulting in substantial ice accumulations across northern half of Osage and extreme northern Washington Co as evidenced in loss of mesonet wind data. This current cluster of storms will be moving out of that area within the next hour, but the recent model trends have additional convection moving into northeast OK after 06z with potential for at least local ice accum greater than 1/4 inch. Drier air will eventually push south across the area late tonight but not before temperatures coll enough for a transition to freezing rain across a large portion of eastern OK and extreme northwest AR. Existing winter weather advisory should cover it, but a quick upgrade to ice storm warning is not out of the question to the northwest of Tulsa if convective trends upstream over the next few hours warrant it. Overall thinking regarding severe weather potential elsewhere tonight has not changed much, as increasing warm advection will force additional storms near and south of the frontal zone. Along and south of the boundary which lies across extreme southeast OK there remains at least some potential for sfc-based updrafts and low tornado potential overnight. Finally, have canceled much of the dense fog advisory as vsbys have mostly improved to 2SM or greater. The exception remains some areas to the SW of Tulsa which could still see greatly reduce vis through midnight. && .PREV DISCUSSION... /Issued 544 PM CST Wed Feb 6 2019/ AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. LIFR conditions will continue at the Oklahoma sites until late tonight, with gradual improvement then expected into Thursday, with VFR conditions returning by late Thursday. Initially VFR conditions at the Arkansas sites will worsen to MVFR overnight, and remain MVFR through much of Thursday. Scattered showers and thunderstorms this evening will become more numerous overnight, before ending from the west late tonight and early Thursday. Some freezing rain will likely occur at the Oklahoma sites before the precipitation ends. Northwest winds will gust to over 20 knots at times during the day Thursday. PREV DISCUSSION... /Issued 426 PM CST Wed Feb 6 2019/ DISCUSSION... Yet another very busy day on the forecast desk. This is what happens when you have a shallow arctic airmass wedged into your area, with a moist Gulf airmass to its south. Models today have trended more aggressive with elevated convective development on the cold side of the front tonight into Thursday morning, and this has increased qpf on the cold side of the southeastward advancing freezing line with time. Thus, have increased ice amounts across northeast Oklahoma and far northwest Arkansas and have expanded the winter weather advisory. Portions of far northeast Oklahoma near the Kansas border could pick up between a tenth and 2 tenths of an inch of icing, while other areas could accumulate up to a tenth of an inch. Combine the heavier icing potential near the KS border with increasing northwest winds behind the advancing arctic front tonight, and there could be some scattered power outages. In between the freezing line and the front sitting over southeast Oklahoma into central Arkansas, areas of dense fog will persist into the evening, reducing vsbys down to a quarter mile or less. A dense fog advisory has been issued thru midnight tonight. Now to the convective forecast. Hi-res data earlier today suggested there was a low probability of supercells near/along the front this afternoon. So far, this has not occurred. As mentioned earlier, the trends in the data suggest more development north of the front tonight compared to previous data. Local model and HRRR continue to show some UH tracks with some of the storms, suggesting that a large hail threat exists. If any storms can develop closer to the front and are more surface based, there would be a low tornado threat as well. The scenario of a robust convective line with the front is not suggested as much today, mainly because the shallow front remains wedged pretty far south in our area today. All of the activity should be east of the region by 6 am. After some quiet days Friday and Saturday, the next precip event will begin Saturday night into Sunday when the warm conveyor precip spreads northeast ahead of the next storm system. Again, it is possible that areas of northwest Arkansas will be near freezing when the rain moves in from the southwest, so a continued mention of light icing continues with this forecast. The main upper system will affect the area Monday night into Tuesday. Based on the track of the system, winter weather impact potential doesn`t look all that high attm. Some light snow accums are possible on the back side of the system before it moves east. Lacy && .PRELIMINARY POINT TEMPS/POPS... TUL 25 29 12 34 / 90 10 0 0 FSM 38 38 18 40 / 100 70 0 0 MLC 31 33 16 38 / 100 30 0 0 BVO 23 27 10 33 / 90 0 0 0 FYV 31 34 10 33 / 100 70 0 0 BYV 42 46 12 31 / 100 80 0 0 MKO 30 30 15 36 / 100 30 0 0 MIO 25 27 10 31 / 100 30 0 0 F10 27 30 15 37 / 90 20 0 0 HHW 49 55 21 45 / 100 60 0 0 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...Winter Weather Advisory until 9 AM CST Thursday for OKZ058- 060>072. Dense Fog Advisory until midnight CST tonight for OKZ060-064>066. Winter Weather Advisory until 6 AM CST Thursday for OKZ054>057- 059. AR...Winter Weather Advisory until 9 AM CST Thursday for ARZ001-010. && $$ SHORT TERM...14