Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/25/18

Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
456 PM MST Sat Feb 24 2018 .AVIATION... 00Z TAF CYCLE An upper level trough will reach the Four Corners tonight, then pass eastward along the CO/NM border on Sunday. The system will steer strong W winds aloft over the area with gusty winds at times at AXX and SRR. The jet stream will gradually shift E of the state on Sunday as a gusty Pacific cold front crosses from the NW. Along and W of the northern mountains tonight into Sunday morning, the storm system should produce areas of MVFR conditions and localized IFR conditions with periods of light snow and mountain obscurations. 44 && .PREV DISCUSSION...303 PM MST Sat Feb 24 2018... .SYNOPSIS... The next storm system is approaching from Utah this afternoon and will deliver another round of light snow to the northern mountains late tonight into Sunday morning. More wind and cold is in store for Sunday with temperatures 10 to 15 degrees below normal. Sunday night will be the coldest night for much of the area since late January. A warming trend will occur Monday and Tuesday with very dry southwest winds. Elevated fire danger will impact much of eastern New Mexico. Another storm system will move into New Mexico Tuesday night and Wednesday with much colder temperatures and more wind. This storm will increase the potential for light snow for most of central and western New Mexico on Wednesday morning. A slow warming trend will develop toward the end of the week. && .DISCUSSION... Widespread windy conditions over eastern NM will taper off through sunset. The current wind highlights will be allowed to expire at 4pm however a few spots may remain close to advisory levels through 6pm. The latest water vapor imagery is showing a well defined upper wave racing southeast toward NM from the Great Basin. Very dry air ahead of this wave has forced surface dewpoints into the single digits and teens below zero over the area. This system is already moisture starved so snowfall will be orographically forced along west facing slopes of the northern high terrain. The 12Z HREF-2, local WRF, and HRRR guidance have low QPF values in line with WPC QPF. Last nights system was an underperformer and this one will likely not make any impressions either. Temperatures however will be very cold so any accumulations could cause slick travel in the northern high terrain. Very dry air with strong surface high pressure and clearing skies in the wake of this system will lead to the coldest low temps since late January for much of the area on Monday morning. The ABQ metro will see lows along the valley floor in the middle to lower teens. Flow aloft quickly backs to the southwest Monday as a 540dm H5 low develops over southern California. 700-500mb layer flow increases to near 30 kts with strong warm advection. A dry slot ahead of this wave will elevate fire danger across eastern NM both Monday and Tuesday. High temperatures will trend closer to or even slightly above normal. Southwest winds will be strongest on Tuesday. 12Z model guidance came into better agreement with the next storm system Tuesday night and Wednesday. The aforementioned upper low is expected to move slowly east across AZ Tuesday night and fill to near 545dm over NM Wednesday. There is meager low level moisture advection so the system will rely on mid/upper level moisture, frontogenesis, and cold core instability. 700mb temps are shown to fall to near -10C over western NM with snow spreading east toward the central mtn chain through Wednesday morning. This will allow for snow in all areas with potential for slick travel. Guyer && .FIRE WEATHER... ...FIRE WEATHER WATCH IN EFFECT FOR MUCH OF EASTERN NEW MEXICO MONDAY... As one upper-level trough exits to the east another approaches from the northwest tonight. Strong west to northwest winds along and east of the central mountain chain this afternoon will subside after sunset but brisk west winds will continue overnight in the higher elevations. Light snow amounts will favor the far northwest plateau and Tusas Mountains late tonight into Sunday morning. Widespread brisk west to northwest winds will develop once again Sunday morning, continuing through early afternoon. Wind speeds on Sunday are forecast to remain below critical thresholds. The exception will be in Curry and Roosevelt counties where an hour or two of critical conditons develop. By Monday, temperatures warm and winds increase once again. Critical fire weather conditons are likely across much of the area along and east of the central mountain chain Monday afternoon and a fire weather watch has been issued as a result. Stronger winds aloft sag over southern NM Tuesday so critical condtions will be harder to come by. Models are now in good agreement with regard to a cold upper low for Tuesday night and Wednesday. Associated surface cold front along with areas of snow are forecast to race eastward across western NM Tuesday evening and across the remainder of the state late Tuesday night. Significant snow and blowing snow are possible in the western and northern mountains Tuesday night into Wedenesday morning. Drier and warmer weather returns underneath zonal flow aloft for Thursday and Friday. 33 && .ABQ WATCHES/WARNINGS/ADVISORIES... Red Flag Warning until 6 PM MST this evening for the following zones... NMZ108. Fire Weather Watch from Monday morning through Monday afternoon for the following zones... NMZ103-104-108. && $$
Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
554 PM CST Sat Feb 24 2018 .DISCUSSION...Updated for latest aviation discussion below. && .AVIATION...Satellite images and surface observations across deep south Texas early this evening indicate some mid to high level clouds over the area. Expect VFR conditions to prevail across the area this evening with breezy southeast to south winds gradually diminishing after sunset. A weak cold front will move into the northern ranchlands tonight and low to mid level moisture will increase ahead of the boundary. Expect MVFR to near IFR conditions to develop with low clouds/fog late tonight into early Sunday morning. In addition...showers and thunderstorms will develop across portions of the northern ranchlands tonight and possibly move into the Rio Grande valley early Sunday morning. Light to moderate winds and MVFR ceilings are expected to linger into early Sunday afternoon. && .PREV DISCUSSION... /issued 307 PM CST Sat Feb 24 2018/ SHORT TERM (Tonight through Sunday Night): Winds continue to gust between 40 and 45 mph across portions of Cameron county and between 30 and 35 mph across portions of Hidalgo county this afternoon. Will continue the wind advisory for the coastal counties of deep south Texas through the rest of the afternoon. The winds will diminish early this evening as the strong low level jet across the lower TX coast lifts northward and the pressure gradient begins to relax as a weak cold front moves into south Texas. Main concern tonight is the convective potential across the northern ranchlands and upper Rio Grande valley as the front moves into the northern and western portions of the CWA late tonight. This morning the HRRR was progging thunderstorms developing across portions of Jim Hogg and Brooks counties tonight but the latest HRRR is indicating southern portions of Hidalgo county before midnight. With lack of mid level moisture and a strong low level thermal inversion across the lower RGV...will keep best rain chances across the northern ranchlands and upper RGV tonight where showers or thunderstorms are more favorable for development. With fairly decent storm relative helicity across the area...will mention gusty winds... small hail...and heavy rainfall with strong thunderstorms across the northern and western portions of the CWA tonight. The front will likely stall somewhere over deep south TX late tonight into Sunday. Will likely see scattered showers and isolated thunderstorms across eastern portions of the CWA Sun afternoon where surface instability will likely be higher with light southerly winds across the lower RGV. The front tries to move across the lower TX coast Sun night and offshore early Mon morning with a convective boundary across southeast portions of the CWA Sun night. Will keep higher POPS across southern and eastern portions of the CWA Sun night as drier air filters into the northern and western portions. LONG TERM (Monday through Saturday): A changeable spring-like pattern fittingly dominates the coming work week, including just about everything from welcome rain early to a heat spike and wind machine in the middle, and perhaps thunderstorms separating the very warm/hot day from a warm breezy and much drier day to follow as March arrives, then back to some clouds and perhaps a little rain to start the next weekend. The changeable weather comes courtesy of a subtle change in the steering pattern t through the week. Though southwest flow still prevails at 500 mb into mid week, the subtropical ridge that has dominated the Gulf of Mexico and kept Florida beautiful and south Texas breezy to windy and generally warm/humid will flatten a bit and begin to shift west, and by late week this ridge axis is centered over Veracruz. At the same time, troughing develops along the mid Atlantic coast, with northwest steering flow reaching Florida and bringing a long-awaited front through most of the peninsula. Why does this matter? It *could* be the start of a trend toward drier fronts and continued warmer than normal temperatures heading deeper into March, which is part of the spring pattern expected to dry out and eventually heat up (in a more notable way) the Rio Grande Valley. Stay tuned. Monday begins with a weak 500 mb short wave/shear axis which helps to develop a weak but important coastal trough just east of the Lower Texas coast. The GFS was initially the most bullish on this solution, but the 12Z deterministic ECMWF came around completely today and given that the potential for light but notable rains especially across the populated RGV makes sense given the big picture, especially since Sunday`s front has minimal southward push of drier air after reaching the ranchlands. With leftover subtropical moisture in the mix have pushed up QPF a few notches, with potential for area-wide .25 to .5 inches across the populated RGV. Temperatures will be a bit tricky; low clouds/light rain and northeast flow should hold readings in the soupy mid 60s to around 70 for the Valley, but with drier air and filtered sunshine farther north and west the mid 70s advertised by the ECMWF is in line as well. Winds continue to veer to the east Monday night but light (5 knots or less) and eventually to light southeast by daybreak Tuesday. With only slight drops in temperature but more importantly dewpoints catching up/remaining for 100 percent humidity, fog, which has been a dominant weather element this winter on the edge of transitions from cool/cold to warm, looks likely to develop. Followed WFO Corpus` lead and added "Areas" mention to entire region except for outer coastal waters, with slow dissipation Tuesday along the immediate coast where marine layer will keep winds suppressed some. As for those winds on land, quick return to south/southeast flow with a pickup to near 30 knots at 850 will get the Valley Wind Machine back in gear - though not as crazy as today`s version which has pumped long durations of 30 to 34 mph gust 40 to 50 mph across the lower Valley. As deeper moisture quickly scoots north, expect a mix of afternoon sun and clouds in most area, and with rapid low level warming low to mid 80s seem like a sure bet, perhaps a few upper 80s sneaking in across parts of Hidalgo and Starr County. Breezy warm weather continues overnight Tuesday into early Wednesday as region is sandwiched between what`s left of subtropical ridge and approaching (but lifting) shortwave trough moving through the southwest U.S. Lows should be in the lower 70s (upper 60s ranchlands) but could be a tad higher if low clouds scoot in, especially across the RGV. This sets us up for a "classic" wind machine/heat spike day on Wednesday. Expect 40-45 mph gusts across the US 77/IH 69E corridor by late morning through afternoon, and with atmosphere quite warm for late February, temperatures should achieve upper 80s to perhaps 90 in a few spots given ample sunshine. Farther west, west to southwest flow at 850 brings the downslope, and surface winds go light. Guidance fairly consistent on 90 to 95 along/west of US 281-IH 69C with highest temperatures near Falcon Dam. Would not rule out the year`s first century mark readings either; guidance often late to catch on and has to deal with late winter climatology where outliers are very difficult to nail down. For now, went 92 to 95 from McAllen through Zapata, but would not be surprise to see this end up in the 96 to 100 range. The aforementioned shortwave trough rips through Texas Wednesday night, with a quick moving wind shift/front surging through Deep S. Texas at some point. GFS/ECMWF in excellent agreement with a mid evening to midnight passage for the ranches, and a midnight to 3 AM or so passage for the Valley. While this is likely to change a bit, the timing of any precipitation (including thunder) will ultimately be an hour or two (not a full six hours as currently forecast) before refreshingly dry air sweeps in. Thursday looks mainly sunny with passing cirrus; the ECMWF is a bit drier but the GFS came toward this solution with the 12Z run. Temperatures will still be warm but dewpoints will be much lower, and we may need to watch combo of afternoon RH and wind for potential wildfire spread issues as we get closer to the event. Clouds gradually increase Friday but still should be enough sunshine and still comfortable humidity with lighter east/northeast winds to make a great end to the work week. Saturday remains uncertain for now; retained the idea of some light rains for the Rio Grande Valley with fairly deep low level moisture (to 800 mb) as weak short wave slides through the flat ridge, which will be centered over Veracruz. MARINE: Seas were generally 5 to 7 feet with south to southeast winds 15 to 20 knots offshore the lower Texas coast this afternoon. Winds will diminish across the coastal waters tonight as a weak cold front moves into south Texas late tonight and the pressure gradient weakens across the lower TX coast. Seas will remain high offshore so will extend the small craft advisory for the 20-60NM waters through midnight but the nearshore waters should be below SCA criteria so will replace with SCA with SCEC after 6 pm. Light to moderate southeast winds will prevail across the lower TX coast after midnight tonight. Winds should remain light from the south across the coastal waters Sunday as the front likely stalls near the coastal bend Sun afternoon. The frontal boundary tries to move over the lower TX coast Sun night and move offshore early Mon morning as a convective boundary. Winds are expected to shift to the north and northeast across the northern coastal waters early Mon morning as a result. Monday through Thursday: A rather yucky boating day Monday with occasional rain/showers and a nuisance stiff northeast wind, along with mixed seas (wind chop and some swell) up to 5 feet expected. A bit better for early morning fishing Tuesday except for potential dense fog (radation/sea fog combo) that could delay trips for those concerned with low visibility, with winds light and seas moderate to start the day. Laguna winds will pick up some Tuesday afternoon, and caution/Advisory conditions for winds possible but will be determined by strength of the marine layer. Winds will pick up Tuesday night in all areas (a bit less over the nearshore waters due to remaining marine layer) and with 850 mb flow possibly reaching 40 to 45 knots advisory conditions (wind and perhaps seas) may develop offshore, continuing Wednesday with 20 knot sustained wind likely in both areas. Even the nearshore could see 20 knot winds for a time, especially mid morning through mid afternoon. A brief lull in winds before shifting northwest/north late Wednesday night and continuing Thursday. With minimal cold air advection over a marine layer, expecting sustained winds over the nearshore waters Thursday to be around the edge of caution (15 to 20 knots) with a better opportunity over Laguna Madre. Seas will hold at moderate to caution (6 foot) levels though northwest flow should drop values a bit nearshore for Thursday. CLIMATE: The heat has dominated February, and after today all primary locations (Brownsville, Harlingen, McAllen) will be somewhere between 5 and 5.5 degrees above the monthly average. With above to slightly above average temperatures through Monday, then a last hurrah of heat Tuesday and especially Wednesday, 6 degrees above average for the month is not out of the realm of possibility. That *could* tip the scales to a winter (December- February) just *above* average - something that seemed unheard of when January ended. We`ll do the numbers in a few days. && .BRO WATCHES/WARNINGS/ADVISORIES... TX...None. GM...Small Craft Advisory for winds until 6 PM CST this evening for GMZ130-132-135. Small Craft Advisory until midnight CST tonight for GMZ170-175. Small Craft Advisory until 6 PM CST this evening for GMZ150-155. && $$ This product is also available on the web at: HTTP://WEATHER.GOV/RGV 63
Area Forecast Discussion
National Weather Service Columbia SC
609 PM EST Sat Feb 24 2018 .SYNOPSIS... Near record temperatures will continue tonight, with high pressure centered off the coast bringing warm and moist air into region. A cold front will cross the area Sunday into Monday bringing a high chance of showers. Temperatures will remain above normal next week. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... The high pressure ridge continues to direct a southwesterly flow into the region. The upstream low pressure system will continue to lift northeastward, tightening the pressure gradient over the Southeast. Expected breezy conditions to persist this evening, but winds should weaken some overnight. A much stronger low level jet and high clouds will make fog less likely than the previous few nights, with stratus more probable. However, cannot rule out patchy fog over southeast portions of the CSRA and eastern Midlands where moisture is very high. Any showers tonight are expected to remain northwest of the area closer to a shortwave moving through the upstate, and the approaching front. Record highs were experienced today, and overnight lows could be near record warmest in places. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/... Sunday: Low pressure over the northern Great Lakes region will move into Canada on Sunday dragging a cold front from the Tennessee Valley across the Appalachians and into the forecast area. Moisture will deepen through the day with increasing chances of rain during the afternoon. The better chance of rain still appears to be Sunday evening and into Sunday night. Lowered pops east some during the afternoon given latest model guidance. Instability appears quite limited during the afternoon with the most favorable LI values near 0, but cannot rule out an isolated thunderstorm. The pressure gradient will tighten on Sunday ahead of the front with breezy conditions expected. Southwesterly winds around 10 to 15 mph with gusts up to 25 mph are expected. A lake wind advisory will need to be considered. Monday: The cold front is expected to be in the eastern portion of the area Monday morning and will slowly push east and off the coast Monday night. Weak low pressure tracking northeast along the boundary from the gulf coast States will focus showers across the area as isentropic lift is enhanced along with low level convergence.Moisture will decrease during the late afternoon from west to east across the area. Models show shortwave energy moving through the area Monday night although the more favorable energy appears much further north and drier air will already be moving into the area. Maintained categorical pops during the day and slight chance east Monday night. Temperatures on Monday will be several degrees cooler than recent days with highs in the upper 60s to around 70 and lows in the upper 40s to lower 50s. && .LONG TERM /TUESDAY THROUGH SATURDAY/... Models show generally zonal flow aloft on Tuesday with surface high pressure centered over the Mid-Atlantic states. This will promote a dry forecast for Tuesday. An upper disturbance along the lower Mississippi Valley region will move toward the area on Wednesday along with a warm front. High pressure will be off the coast promoting easterly low level winds. Have continued to indicate likely pops west and chance pops east for Wednesday and Wednesday night. An upper low and and associated surface low will move from the Upper Mississippi Valley region on Thursday towards southern New England by Friday bringing the next cold front through the forecast area. The front will be off the coast on Friday with an upper ridge and surface high pressure building back into the area for the end of the week. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... VFR conditions expected to continue for much of the overnight hours, with a return to mvfr ceilings/visibilities between 08-11z Sunday. Scattered mid-level cumulus fields will dissipate after sunset, leaving mostly clear skies for a portion of the overnight hours. Model time sections showing a stronger low-level jet developing after 00z tonight, with strong 25-30 knot winds near 2kft helping with mixing. Winds more out of the south to southwest overnight also, with less Atlantic moisture than previous nights. Latest hrrr model run showing only patchy fog towards morning, with highest probability moving in from southwest of the CSRA. The same thinking follows with the lower ceilings moving in towards morning from the southwest prior to sunrise. Will trend towards that solution. VFR should return by late Sunday morning. With a cold front approaching from our west tomorrow, area should once again see an increase in wind speeds. Southwest winds will be from 10 to 15 kts with gusts up to 20 kts after mid-morning. EXTENDED AVIATION OUTLOOK...A cold front will move across the region Sunday night into Monday bringing potential for associated restrictions in rain. Another frontal system may bring restrictions on Wednesday. && .CLIMATE... Record heat today, with near record heat possible tonight. CAE set a new record high for 2/24 of 83, breaking the old record of 82 set in 2017. CAE warmest low for 2/25 is 61 last set in 1890. AGS tied the the record high for 2/24 of 84, last set in 2017. AGS warmest low for 2/25 is 61 last set in 1918. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. && $$
Area Forecast Discussion
National Weather Service Caribou ME
1052 PM EST Sat Feb 24 2018 .SYNOPSIS... High pressure will build across the area through tonight. A frontal system will move through the region later Sunday into Sunday night. High pressure will then build back in through mid week. && .NEAR TERM /THROUGH SUNDAY/... 1050 PM Update... Satl IR imagery showed high clouds streaming e across VT/NH and headed toward ME. Adjusted the sky conditions to show high clouds moving in overnight. NW winds were still up 10 to 15 mph across the northern areas helping to keep temps up. Given the latest obs and trends, decided to bring overnight mins up a few degrees as temps were warmer by at least 3 degrees from the previous forecast. Still expecting the sites back across NW Maine to drop below 0F mainly in the low lying sites. The rest of the region in the single numbers and lower teens due to some mixing of the llvls w/winds staying up a bit longer. The latest RAP matched up well w/this setup. Previous Discussion... 1026mb sfc high sitting just north of Ottawa Ontario wl continue building east drg the ovrngt hrs. This wl allow clds to dissipate this evng with loss of diurnal htg and with winds bcmg near calm radn`l cooling wl allow temps to drop blo 0F acrs cldr vly locations in the North Woods. Min ovr nrn Aroostook wl appch zero in notoriously colder locales. S/wv mvg thru OH valley this aftn and bringing rain to portions of the northeast wl skirt well south of CWA as high blocks nwrd mvmnt. Next system on tap to spread pcpn into the region is currently spinning acrs the nrn Plains. High cirrus wl begin to appch swrn sxns twd daybreak with winds veering around to serly direction in advance of sfc bndry. Overrunning pcpn lkly to start by mid-mrng Sun and spread north and east fm there thru the aftn hrs. As pcpn begins entire airmass wl be blo 0C with ice in the cld. As the aftn progresses into evng, expect that dendrite lyr wl lose moisture leaving drizzle/freezing drizzle in its wake twd the late aftn hrs. Snow drg the aftn looks to be fm 1-3 inches bfr cld loses ice and turns to more of a drizzle scenario. Wl allow later shifts to refine timing of frzg drizzle and issue winter weather advisory for tomorrow afternoon/evening. Expect that high temps on Sun wl top out right around normal for this time of year. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... Snow will be ending early Sunday evening and remaining precipitation will transition to freezing drizzle with less a tenth an inch of ice accumulation. The decaying warm occlusion will allow cold air damming to persist through the night. With a good supply of low level moisture...and none of it at levels colder than -10C...freezing drizzle seems like the most likely outcome. The exception will be towards the coast where temperatures will be above freezing on Sunday night. No diurnal curves were necessary for Sunday night temperatures as readings will tend to rise overnight. The freezing precipitation may prompt advisories rather than the modest snowfall from this system. On Monday morning, a drying southwest wind will scour the frontal inversion and high pressure will build eastward from the Ohio River Valley region. Cold air advection aloft will prompt gusty winds and cumulus development by afternoon with isolated snow showers possible. After the relatively mild lows Monday morning, temperatures will rise into the 40s for most of the area by early Monday afternoon. Moisture will refreeze Monday night as temperatures fall into the 20s, but the air mass is not particularly cold and highs will return to the upper 30s and 40s on Tuesday. More gusty NW winds and cumulus development are anticipated by Tuesday afternoon. The high pressure ridge will crest over the area later Tuesday afternoon. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... A weak clipper system will affect the forecast area Tuesday night into Wednesday. At this time, will go with no more than slight chance pops and mostly cloudy skies. It`s a small-scale system with little moisture and little model consensus. The relatively mild pattern will continue as a zonal pattern transitions to a blocking pattern dominated by a large upper level high retrograding from the north Atlantic into eastern Canada. This high will cause a moist and mild flow of maritime air into the area by later in the week. The high looks like it could suppress a vertically stacked low pressure system to the south of the forecast area later in the week. However, in dealing with the evolution of a cut-off low at nearly 144 hours out, it`s certainly possible it could drift further north into the area. && .AVIATION /04Z SUNDAY THROUGH THURSDAY/... NEAR TERM: VFR next 24 hours as low VFR cigs dissipate with building high pressure around 00z. Next system affect BGR and BHB very late in the TAF period with a return of VFR cigs after 16z. NW winds gust to near 16-20kts this afternoon bfr diminishing this evening. SHORT TERM: IFR cigs and vis are expected Sunday night with snow changing to freezing drizzle. VFR conditions return for all terminals on Monday into Thursday. There is a chance of IFR vis in snow north of HUL Tuesday night. Chances for widespread MVFR cigs increase towards Thursday. && .MARINE... NEAR TERM: Winds will increase to aoa 25kts after 06z tonight for the outer waters and for the intracoastal zones twd 12z thus an SCA has been issued thru the day Sunday. Winds may approach gale conditions late in the afternoon for a brief period of time. Seas will build late in the afternoon in serly swell. SHORT TERM: SCA conditions will continue Sunday evening and end later in the night. The next marine threat will occur towards Friday into Saturday when a gale is possible. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...None. MARINE...Small Craft Advisory from 7 AM Sunday to 1 AM EST Monday for ANZ052. Small Craft Advisory until 1 AM EST Monday for ANZ050-051. && $$ Near Term...Hewitt
Area Forecast Discussion
National Weather Service State College PA
954 PM EST Sat Feb 24 2018 .SYNOPSIS... Periods of rain will continue late tonight through mid-day Sunday. The rain could be heavy at times. Saturated ground and swollen streams will support an elevated risk for flooding through the weekend. A break in the wet weather pattern is expected early next week. Above average temperatures are expected to continue through much of next week before a relative cooling trend toward climatology into early March. && .NEAR TERM /UNTIL Noon SUNDAY/... After about a 6-8 hour lull in the steady light to moderate rain, the leading edge of the next shot of moderate to strong forcing and high PWAT air of 25-30 mm (which is in the range of plus 3-4 sigma) will move NE and into the western half of the CWA before midnight. The are of rain will expand across the rest of the CWA between 05-07Z. The heaviest rainfall based on the latest RAP and SPC`s HREF, we expect the heaviest rain of about 0.75-1.00" to fall across the Western Mtns of PA between 05-11Z Sunday and across the Central part of the CWA within the 07-13Z window, and over the East between 08-16Z. Some locations will see an additional 1.5 inches of rain by later Sunday morning (west) and early afternoon (East). Temps won`t move much overnight from their early evening Low- Mid 40s levels, but a deg F or two of rise is possible through the rest of the night as winds increase and readily break any weak llvl inversion that exists. Based on regional MRMS (Radar + Gauge Bias Correction) data, that shows 0.75 to 1.25 inches over the past 48 hours across much of Central and Northern PA (with only 0.10-0.40 in the south), we`ve already received about half of our rainfall for this prolonged event. This should bode well for flooding concerns, which should not increase from what we advertised for the past few days. See hydro section near the bottom for additional details on the potential for primarily small stream and creek flooding. Stability decreases across wrn PA late tonight but then skirts around most of the CWA as it is confined to S of the MD border through the rest of the morning. Will not mention T at this point. While the air will be drying out Sunday night, the wind won`t be all that gusty, and temps don`t crash. High builds over the OH vly through the night, and gradient slackens. 8H temps of 0 to -3C are still rather mild for Feb. Mins of u20s NW and 30s elsewhere look solid. && .SHORT TERM /SUNDAY Afternoon THROUGH SUNDAY NIGHT/... Air dries out quickly after 9 or 10 AM (14-15Z) in the west and 17-19Z (east), as colder air pushes in from the west on a moderately gusty west wind before noon. Residual SHRA over the Laurels will dissipate about the same time as the main batch of showers exits to the east with drying in between beforehand. Again, the sfc instability stays just south of the MD border through the morning. Can`t rule out an isold Tstorm in the south in the morning, but probably not worth mentioning at this point. Temps do rise 5-10F through the day, esp if some breaks occur in the aftn, but this could be squelched over the west as the cold air arrives there first. && .LONG TERM /MONDAY THROUGH SATURDAY/... The wet pattern looks like it will take a break during the first part of next week before precip risk increases next Wed-Fri. Mild and dry for Mon through Tue night as high pressure ridge will be in control. Model and ensemble guidance show a low pressure system tracking east-northeast from the TX/OK panhandle across the Central Plains/Midwest into the Great Lakes/Ohio Valley region by Thursday. The ECMWF and GFS 12z runs beginning to converge on a similar overall solution of strength and timing. First up will be a warm front lifting through Thu night which could bring a period of moderate rain to the area, and have raised pops further during this period. Then attention turns to development of a secondary low to the south of PA from the southern Mid Atlantic piedmont that potentially settles in near the NJ coast for a 12-24hr period Fri into Fri night. This is starting to look more and more like we`ll have potential ptype issues or wintry wx - esp over the northern half of CWA as colder drier air wraps in from the NE. Could see accum snows in those areas, and likely breezy conditions for the weekend. Something definitely to watch at this range. Temperatures will continue to run above average next week with signs of trending cooler/closer to daily climate normals into early March. && .AVIATION /02Z SUNDAY THROUGH THURSDAY/... We`ll have a several hour lull in the steady rain in most places this evening as one wave of weak low pressure moves quickly east to Southern new England. A second wave of low pressure, associated with a plume of a high moisture values spreading NE from the Ohio River Valley, will takes aim at Central PA overnight and Sunday morning. Expect any MVFR or low end VFR this evening across parts of the Middle Susq Valley and Central Mtns to be fleeting and drop steadily into the IFR/LIFR category late this evening through the overnight hours. Conditions will return to quickly MVFR then VFR from west to east across most or all of the region Sunday afternoon/evening, though some intermittent MVFR cigs are possible at KJST and KBFD during that period as shallow cooler air ascends the Alleghenies. Winds aloft will increase to 50 kts at 2,000 AGL so LLWS is possible overnight. These winds will make it to the surface with gusts to 20 kts at times. Outlook... Sun...Widespread restrictions likely in periods of rain. Mon-Wed...No sig wx. Thu...Restrictions possible in periods of rain. && .HYDROLOGY... Plume of moisture from Pac and GOMEX continues to flow overhead. Forcing comes in many waves with a very weak concentration at any one point. Instability will remain limited due to all the clouds and E/SE sfc wind flow. Wet ground, already-high streams and the anticipated rain will push many locations above their caution stages, and a few will approach and perhaps exceed flood stage. However, rain does look a little less in some places than prev forecasts. It looks fairly evenly distributed from this point on. Biggest risk remains for a widespread rise on all the small creeks and streams. The larger creeks will be a slightly lesser worry, but will be the biggest worry for any river forecast points. The mainstem and larger river flooding is the least of the worries. && .CTP WATCHES/WARNINGS/ADVISORIES... Flood Watch through Sunday evening for PAZ004>006-010>012- 017>019-024>028-033>037-041-042-045-046-049>053-056>059- 063>066. && $$ SYNOPSIS...Dangelo/Lambert NEAR TERM...Lambert SHORT TERM...Dangelo/Lambert LONG TERM...RXR AVIATION...Lambert/Gartner HYDROLOGY...Lambert
Area Forecast Discussion
National Weather Service Hastings NE
523 PM CST Sat Feb 24 2018 .SHORT TERM...(This evening through Sunday) Issued at 245 PM CST Sat Feb 24 2018 Hazardous Weather: None. Aloft: RAP analyses and 12Z upr-air data show a longwave trof was over the Wrn USA with a couple shortwave trofs embedded. The 1st was over the Nrn/Cntrl Plns and was responsible for the -SN/-FZDZ today. The 2nd was diving down the backside of the trof over the Pac NW. The initial trof will exit to the E this eve while the upstream trof conts SE. This trof will cross the rgn tomorrow with heights temporarily building over the Wrn USA in its wake. Surface: The main polar front extended from TX to the OH Vly with low pres over MO. A weak sfc trof was progressing across Neb/KS and it will become absorbed into the MO low this eve. Weak high pres over the Srn Plns will build in tonight. That high will head into the SE USA tomorrow but still extend back into the Cntrl Plns. This ended up being a minor winter event...nothing like it look for svrl days earlier this week. Quite a dud if you`re a fan of snow. At any rate...the last few bands of -SN have shifted to roughly Hwy 281 and will cont to head E the next 1-3 hrs. Plan to let the advisory expire at 22Z. Tonight: m/clear in the eve but some mid-high clds will invade from the W after midnight preceding the approaching trof. So skies will turn p/cldy. Lows will be in the teens. Clearing this eve in the presence of high low-lvl moisture suggests fog could be a problem...but good mixing is occurring in the sunshine to the W. Dwpts are tanking as a result and this dry air is fcst to advect in here. That should mitigate the fog threat tonight into Sun AM. Sun: P/cldy thru midday then gradually decreasing clds from the NW. Temps will rebound back to normal. The warmest day we`ve seen since last Sun. .LONG TERM...(Sunday night through Saturday) Issued at 245 PM CST Sat Feb 24 2018 Potentially Hazardous Weather: Critical fire wx Mon. See fire wx section below. Aloft: The Wrn trof will reload Sun night into Mon with the last 2 EC/GFS/GEM runs breaking off a low over Srn CA Tue. This will put the CWA in WSW flow. Current indications are that the Desert SW low will open up and swing thru KS/OK Wed. This time frame needs to be watched. The models are fcstg cyclogenesis but further downstream than usual. That seems odd. Even weakening trofs coming out of the SW needs to be watched. If lee cyclogenesis is induced further W ...that is how we get our biggest snowstorms here. Suggest not writing this off just because the models don`t have it. A ridge should develop over the Plns Thu-Fri as the Wrn trof reloads again and it could eject a potent trof across the CWA next weekend. Surface: A weak cool front will move thru Tue with weak high pres building in from the N Tue-Wed. Cyclogenesis is fcst SE of the CWA along the front Wed. This low will head into the GtLakes Thu with high pres overhead. That high will gradually shift E of the rgn Fri-Sat with return flow developing. Temps: Much warmer than normal Mon and highs were raised above the fcst init...especially over N-cntrl KS. Then temps will average near or warmer than normal thru next Sat. One or two of those days could also be much warmer than normal. Precip: Depending on the eventual track of the low to the SE...some precip could fall here Tue night into Wed as that low evolves. Other than that it`s looking dry all other periods. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Sunday) Issued at 521 PM CST Sat Feb 24 2018 MVFR ceilings have moved out of the terminals in the past couple of hours. There could be a few mid level clouds around, but most of them will be during the day Sunday. Gusty west winds will diminish as the sun goes down this evening. && .FIRE WEATHER... Issued at 245 PM CST Sat Feb 24 2018 Watch issued for all of N-cntrl KS and Furnas/Harlan counties in S-cntrl Neb. Very warm day with mixing to between 4500-5500 ft. That will mix dry air and winds to the ground so that RH will drop below 20% and S winds will be sustained 20-25 mph with gusts to 35 mph. Those are Red Flag conds. So coordinated with GLD/DDC to issue a watch. && .GID WATCHES/WARNINGS/ADVISORIES... NE...Fire Weather Watch from Monday afternoon through Monday evening for NEZ082-083. KS...Fire Weather Watch from Monday afternoon through Monday evening for KSZ005>007-017>019. && $$ SHORT TERM...Kelley LONG TERM...Kelley AVIATION...JCB FIRE WEATHER...Kelley
Area Forecast Discussion
National Weather Service GRAND JUNCTION CO
441 PM MST Sat Feb 24 2018 .SHORT TERM...(Tonight through Sunday night) Issued at 204 PM MST Sat Feb 24 2018 The next fast-moving trough is spreading high clouds across northeast UT and northwest CO late this afternoon. This trough was strengthening over the Great Basin with a strong jet rounding the bottom of the trough and providing good uplift over NE UT. The HRRR and HiRes bring precipitation into the mountains of NE UT by 03z and this spreads to all the CO mountains by 06Z. Most of the area will be under the moist and unstable area between the 700 mb and 500 mb trough between midnight and 6 AM. 700 mb temps will range from -12 C to -16 C so this quick shot of snow should produce up snow accumulations just shy of advisory amounts. Areas above 9500 ft will see higher amounts but no winter weather products appear needed at this time. After a cloud and snowy start Sunday morning, clearing skies will quickly spread across the area from west to east. Sunday should be clear and cold and have adjusted many high mountains valley temperatures down. .LONG TERM...(Monday through Saturday) Issued at 204 PM MST Sat Feb 24 2018 Monday and Monday night should be dry with NW flow aloft and a splitting trough digging along the west coast and northern Rockies. The southern portion of the split is projected to close off at 500 mb and meander over the southern U.S. border. The GFS closes the low off too but is more progressive. Tuesday through Wednesday the northern and southern portions of the split stay in sync and move across UT and CO bringing a 48 hour period of snow for the mountains and most valleys. Dynamics and orographic snow will be weaker though because UT and CO will mainly under a deformation zone between the two components of the split trough. Another trough is projected to move through the area Friday and Saturday. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 426 PM MST Sat Feb 24 2018 Clouds continue to stream into the area from the northwest ahead of the next weather maker. For now, all TAF sites are reporting VFR but this will change from 06Z onwards as ILS ceilings will be met for many TAF sites. The mountain TAF sites will likely get close, if not reach, MVFR conditions overnight as snow and snowshowers move in. Flight conditions will improve after 16Z as the storm exits the region. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...None. UT...None. && $$ SHORT TERM...CC LONG TERM...CC AVIATION...TGR
Area Forecast Discussion...UPDATED
National Weather Service Green Bay WI
703 PM CST Sat Feb 24 2018 New Information added to update section .UPDATE... Issued at 703 PM CST Sat Feb 24 2018 Updated the wind advisory to include counties adjacent to Lake Winnebago including Winnebago and Calumet counties. Some potential gusty wind locations include north/south roadway bridges of highway 41, higher terrain of Calumet county by Lake Winnebago. Brown county appears to have less of a threat to reach criteria but still close. Air surface temps dropped to around the freezing mark early this evening prior to the precipitation, but locations not in the advisory should warm up enough. No other headline changes at this time. && .SHORT TERM...Tonight and Sunday Issued at 228 PM CST Sat Feb 24 2018 The latest RAP analysis and satellite/radar imagery show an area of strengthening low pressure moving northeast over southwest Missouri early this afternoon. This low is developing ahead of a sharp shortwave trough extending southeast across the north- central Plains. Strong convection is developing ahead of the low over southern Missouri and Arkansas. Meanwhile, isentropic ascent is increasing over the southern Great Lakes, with snow occurring over southern Minnesota and northern Iowa. Light returns over southern WI do not appear to be reaching the ground just yet. But as the low moves closer, light precip is anticipated to be approaching central WI by later this afternoon. As the low moves across the region tonight, snowfall amounts and gusty winds are the main forecast concerns. Tonight...A potent, negatively tilted shortwave trough will push a strengthening area of low pressure northeast across the area. Ahead of the low, increasing moisture transport in the mid-levels will help spread precip from southwest to northeast across the region from late afternoon through mid-evening. However, the heaviest precip should occur from mid-evening through the mid- overnight hours, just ahead of the potent vort max and surface low. Warm air will surge northward into parts of central and most of northeast WI during the evening, which will keep precip types south of a Wisconsin Rapids to Marinette line as mostly rain with some snow/sleet mixed in. Areas to the north will see mostly snow, and snowfall rates could reach an inch per hour at times during the peak snowfall period. Forecast amounts didnt change much from the previous forecast, though did increase an inch or two from Langlade and Menominee to Marinette counties. As a result, added southern Marinette into the advisory since northern parts could reach up to 5 inches. In general though, a widespread 3 to 6 inches will be possible, with slightly higher amounts over Vilas and Oneida counties. As snowfall diminishes late tonight, strong pressure rises will arrive behind the deepening low. Combined with cold advection and a tightening pressure gradient, will see southwest winds become strong and gusty. Some gusts over the Fox Valley and Lakeshore could approach 40-45 mph range by 6 am. Sunday...Some light snow or freezing drizzle may linger for the first few hours of the morning over far north-central WI. Little to no additional accumulations are expected. Otherwise, the big story will be the strong gusty winds. Wind gusts should peak during the morning, with gusts between 30 to 40 mph possible for most of the area, and up to 45 mph near the Lakeshore. Will hoist a wind advisory from 10-21z for the Lakeshore, though it may be cancelled a little early once the max pressure rises move through around midday. With increasing sunshine though the day, highs will warm into the upper 20s over north-central WI to the mid 30s over eastern parts of the state. .LONG TERM...Sunday Night Through Saturday Issued at 228 PM CST Sat Feb 24 2018 The weather pattern will start off with zonal flow and a weak ridge of surface high pressure over the region. Dry and milder conditions are anticipated through Monday night, with only a small chance of showers as a weak cold front arrives on Tuesday. The front is expected to stall out Tuesday night and Wednesday, with weak overrunning leading to light rain/snow development over mainly the southeast half of the forecast area. Mild temperatures will continue, with highs in the upper 30s to middle 40s. A sharp upper trof crossing the central Rockies will induce cyclogenesis near the Oklahoma Panhandle on Wednesday. This low (and the associated deepening upper trof/low) will track northeast along the stalled frontal boundary, and approach the western Great Lakes late Wednesday night into Thursday. The GFS is farther north with the sfc/upper lows, and brings the potential for heavy snow into GRB CWA, while the ECMWF is farther south and keeps the main impacts to our south. Surface and 850 mb temperatures support mixed precipitation, especially early in the event, with CAA and possible dynamic cooling resulting in a changeover to all snow during the late afternoon or evening. Strong northeast to north winds are also anticipated, along with the potential for Gale Warnings Thursday and Thursday night. Will continue to mention this system in the HWO, but hold off on any specific details at this time. Quiet weather is expected to return as high pressure arrives Friday into Saturday. && .AVIATION...for 00Z TAF Issuance Issued at 536 PM CST Sat Feb 24 2018 Conditions will deteriorate rapidly this evening as a storm system tracks across the western Great Lakes region. Expect a several hour period of heavy snow west of a Wausau to Iron Mountain line, and a mixture of snow, sleet and freezing rain further east. Mostly rain is expected near the Lake and Bay. Low level wind shear is expected tonight. Precipitation will end Sunday morning along with improving vsbys and cigs, however in the wake of a cold front, strong west surface winds of 20 to 30 knots will develop along with gusts between 30 to 40 knots. The higher gusts are expected near Lake Michigan and perhaps counties adjacent to Lake Winnebago. && .GRB WATCHES/WARNINGS/ADVISORIES... Wind Advisory from 3 AM to 3 PM CST Sunday for WIZ022-039-040- 048>050. Winter Weather Advisory until 6 AM CST Sunday for WIZ030-031- 035>037. Winter Weather Advisory until 6 AM CST Sunday for WIZ011>013- 018>021-073. Winter Storm Warning until 6 AM CST Sunday for WIZ005-010. && $$ UPDATE.........TDH SHORT TERM.....MPC LONG TERM......Kieckbusch AVIATION.......TDH
Area Forecast Discussion
National Weather Service Houston/Galveston TX
555 PM CST Sat Feb 24 2018 .AVIATION [00Z TAF Issuance]... KCLL/KUTS...Main concern the next 6 hours will be the cold front and line of convection along it that is currently near near Killeen/Temple area NW of the terminals. Capping is still strong enough per latest AMDAR aircraft soundings, but this convection seems to have broken what little cap there is along the front. The key is outflow/front is out running the convection so it may not last more than the next hour or two. For now will go with SHRA along the front which should push through 02Z. Ceilings may drop to MVFR ahead and just behind the front and gradually improve. VFR ceilings continue into the day Sunday but another short wave trough should be enough to trigger another rough of showers. NAM/GFS highlight this second round of showers and may deserve more attention with the 06Z TAF update. KCXO/KIAH/KHOU/KSGR...Showers will be possible the next 6 hours at the terminals but only passing at that. The main question from 06Z to 12Z Sunday will be convection. NAM/GFS seem to be a bit more aggressive with convection than the convective allowing models like the WRF ARW/NMM and HRRR. Inclined to lean more on those models for convective trends which don`t show much. That makes sense due to the cap but need to be wary of the short wave trough coming into the area by 12Z Sunday. For now will leave showers in the forecast but will continue to evaluate convective trends. Ceilings should drop ahead of the front. Front does reach KCXO around 06Z and then Houston area around 08-10Z. HRRR really slows down the front along the coast while other models push it to the coast. Given moisture MVFR/IFR conditions likely especially for KSGR/KHOU. Still a chance for those conditions at KIAH. Rain chances ramp up again after 15Z Sunday and may need to be stronger in the TAF for showers for the 06Z update. KGLS/KLBX...Sea fog and IFR conditions will likely be the main concerns for the next 6 to 12 hours. Front reaches the coast close to 12Z with a around of convection. May need to added TSRA for KLBX TAF in the morning in addition to KGLS which already has it. This seems more likely with higher moisture along the coast and the better lift from the short wave coming into the area. Showers likely continue through the day Sunday, but will be a matter of amending TAFs for TSRA. Ceilings will be an issue and hard to time when there will be any improvement. Most likely time will be during episodes of convection. Overpeck && .PREV DISCUSSION /Issued 344 PM CST Sat Feb 24 2018/... .SHORT TERM [Tonight Through Monday Morning]... Will be letting the Wind Advisory expire at 4 PM based off trends in observations over the last few hours. Winds have taken on more of a southwesterly component along the prefrontal trough out ahead of the main cold front this afternoon. Radar imagery has revealed linear convection consistently redeveloping along the prefrontal trough, oriented parallel to upper level flow with 500mb winds also out of the southwest. In north central Texas, radar imagery is already showing a line of showers and thunderstorms developing along the main frontal boundary, which should arrive in our northern counties shortly after sunset. The area of low pressure tied to the frontal boundary, is expected to continue pushing off towards the northeast this evening. Short term guidance is such as the HRRR and Texas Tech WRF indicate this line of scattered thunderstorms north of the Trinity to Washington County line possibly arriving between 00Z to 03Z as the frontal boundary sags southward. This arrival is a little faster than trends indicated on radar through simple extrapolation of overall movement. Strong gusty winds and low level rotation will also be possible within stronger cells mainly north of I-10 this evening, as determined through the analysis of the following severe weather parameters. Low level wind sheer especially north of the Washington to Trinity county line, has been pushing 30 to 35 mph this afternoon. The RAP13 shows the region of best effective bulk sheer pushing southward towards I-10 this evening, indicative of possible gusty winds. As the front sags south through the evening hours, scattered thunderstorms will be possible mainly north of I-10 where there is ample moisture and decent instability out ahead of the main frontal boundary. In terms of instability, forecast soundings for IAH indicate both surface and MU CAPE values near 1000-1500 J/kg. Lapse rates between the surface and 3 km range between 6.0 to 6.5 deg C/km, while mid-level lapse rates appear even more favorable for instability with values closer to 7.0 deg C/km. Low level rotation will also be possible within stronger storms, given the storm relative helicity (SRH) values ranging between 150-250 m^2/s^2. Although the all of the ingredients for a few strong storms are there, the lack of low level convergence could dampen overall coverage of these showers and thunderstorms. Therefore, will have to keep a close eye on radar trends this evening for the possibility of these stronger storms developing mainly before midnight as the frontal boundary moves southward. While showers and isolated thunderstorms will also be possible tonight as the shallow cold front slides south of I-10, the chance for tapping into the best instability and decent wind shear lessens the closer you move towards the coast. Although the chance for some gusty winds below stronger cells still remains, the concern for a severe wind threat will transition more into the possibility for training cells after midnight. Where this training sets up will heavily depend upon the location at which this cold front stalls out, transitioning to a stationary front. At 500 mb an region of high pressure located over the northeastern Gulf of Mexico also helps to block the cold front from pushing any further southward off the coast Sunday. Both the 12Z runs of the NAM and GFS show the cold front stalling out just north of the coast between 12-18Z Sunday. As a result, this stationary front will act as a forcing mechanism, providing lift for shower and isolated thunderstorm development along the boundary. Upper level flow remaining parallel to this boundary, will also act to provide good support for training showers and thunderstorms. The concern for convection south of this boundary will be possible beginning in the early morning hours Sunday morning and continuing into Sunday afternoon. Near record breaking precipitable water values exceeding 1.8 inches will be possible along the upper Texas coast. Locally heavy rainfall cannot be ruled out, as both global and short term guidance hint at a decent swath of 1-2 inch rainfall across the coastal counties by Sunday morning. This area of training convection over the coastal counties could begin shortly after midnight. Because of the inconsistencies in vertical accelerations amongst guidance, it remains unclear the duration from which this rainfall will occur. The longer the duration at which these 1-2 inches of rainfall occurs, the less of a chance we will see any localized impacts such as ponding on roadways. While if this duration is over a shorter time scale, localized impacts will be possible. The stationary front will slowly slide back north Sunday morning, increasing the chance for precipitation once again across and slightly north of I-10. Therefore, this region including the City of Houston will also have the possibility of receiving 1-2 inches of rainfall accumulation by Sunday afternoon. Overhead, southwesterly flow aloft will also help continue to advect upper level disturbances across the region, providing dynamic forcing and lift through late Sunday. These upper level disturbances can be seen in water vapor imagery stretching from northeast Texas, southwestward through northern Mexico. A reinforcing area of surface high pressure will build in behind the front boundary late Sunday into early Monday morning, helping to finally slide this feature off the coast. Upper level ridging will also help to send the frontal boundary south of the region, as 500 mb winds turn more easterly. This should make for a much drier day Monday, with precipitable water values lowering to 0.8-1.3 inches across southeast Texas. The chance for patchy fog over the coastal waters will remain in the forecast until this frontal boundary is able to push off the coast Monday morning. With water temperatures around Galveston Bay in the upper 60s to low 70s, there will be less of a chance for patchy fog becoming dense. More information on fog development is provided in the marine section below. Hathaway .LONG TERM [Tuesday Through Saturday]... Behind the cold front, Monday will shape up to be a nice day with high temperatures in the low to mid-70s, partly cloudy skies, and rain chances staying well offshore. The wind will veer to southerly on Tuesday as once again, the boundary from Sunday recedes inland as a warm front, bringing back Gulf moisture and dew points well into the 60s. The combination of this enhanced moisture with a series of upper-level disturbances and good dynamic forcing will increase rain and isolated thunderstorm chances Tuesday afternoon and evening. Chances for showers and thunderstorms remain through Thursday as our next cold front passes through the area mid-week. Confidence for timing the surface front is low, so a chance for showers and thunderstorms is kept from Wednesday morning through early Thursday. Behind the cold front, northerly winds will knock our temperatures back down near climatological average for this time of year (lows in the 50s, highs around 70). Winds will slowly veer to easterly through the weekend as a surface ridge moves into the area from the west. This high pressure system will keep rain chances low and allow for a slow warming trend through early next week. 22 .MARINE... Platforms show visibilities in the 3-4 mile range this afternoon and with winds across the coastal waters almost due south would not expect and resurgence in the sea fog until winds begin to back ahead of a cold front closer to sunset this evening. Expect the cold front to make a run for the coast near sunrise on Sunday with winds backing to the east or possibly northeast in the vicinity of the boundary. Periods of showers and thunderstorms are expected along the coast tomorrow as a result of the front. Water temperatures have warmed into the 66-71 degree range this afternoon, which in addition to the rain will help limit the dense fog threat, but brief windows may still exist as an easterly or northeasterly flow allows for some of the cooler shelf waters off southwest Louisiana to be pushed towards Southeast Texas. Expect the front to be nudged off the coast Monday morning as surface ridging skirts Texas with the potential for sea fog returning on Tuesday as the cold front lifts inland as a warm front. Huffman && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 53 64 50 72 53 / 30 60 20 10 10 Houston (IAH) 61 64 55 74 58 / 60 80 30 10 10 Galveston (GLS) 65 68 61 71 62 / 80 60 50 20 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...None. GM...SMALL CRAFT SHOULD EXERCISE CAUTION until 6 PM CST this evening for the following zones: Coastal waters from Freeport to the Matagorda Ship Channel out 20 NM...Coastal waters from High Island to Freeport out 20 NM...Waters from Freeport to the Matagorda Ship Channel from 20 to 60 NM...Waters from High Island to Freeport from 20 to 60 NM. && $$ NEAR TERM...08 SHORT TERM...22 LONG TERM...Huffman AVIATION...Overpeck
National Weather Service Jackson KY
800 PM EST Sat Feb 24 2018 .UPDATE... Issued at 745 PM EST SAT FEB 24 2018 Convection continues to stream from southwest to northeast across portions of central and western TN and KY. The discrete cells that were closer to the I 65 corridor and track into the Bluegrass earlier this evening have weakened, with heavier rain rates noted in convection near I 65 over the past couple of hours. Cells further southwest over parts of western KY and TN remain strong to severe along a line. Across East KY, there has mainly just been some sprinkles falling from mid clouds this evening. Winds above 2500 feet have been a bit gusty, sustained at 15 to 20 mph with gusts of 30 mph or better at times. Convection will continue to move east northeast toward the area this evening and should remain strong to possibly severe as it approaches East KY. Dewpoints and instability do decrease further east so uncertainty remains in both timing and how strong it may be when it reaches the area. The convective allowing models such as HRRR and ARW appear close though they may be around an hour slow in moving the convection east. With this in mind, strong convection may approach the Lake Cumberland region by midnight. Damaging winds would be the main threat. Only some slight adjustments to timing of higher pops was made to account for recent trends with the remaining hourly grids adjusted for recent trends. Winds and wind gusts for the remainder of the night were increased over the higher terrain above 2500 feet. Convection is expected to be more progressive when it reaches East KY, but rain rates will also need to be monitored. && .SHORT TERM...(This evening through Sunday night) Issued at 458 PM EST SAT FEB 24 2018 Precip has finally just about left the southeast part of the forecast area, just in time for a reload coming out of central KY. The showers and thunderstorms to our west are occurring as warm/moist advection increases ahead of a cold front, and the flow impinges on a warm front laid out from WSW to ENE across KY. Some of this activity may affect the northwest portion of the JKL forecast area this evening, well ahead anything attributable to the long anticipated cold front. The northwest part of the area still looks to be the most at risk for any hydro problem based on expected rainfall and antecedent conditions, and the Flood Watch is being allowed to continue. A band of showers near the cold front will affect the entire area late tonight into early Sunday morning. Instability looks marginal and barely supportive of thunder. However, environmental winds will be very strong, and any mix down could cause problems, even from intense rain showers. The cold front will exit to the east on Sunday and any showers lingering in the morning will end. Clouds will break up during the day as high pressure builds in from the west. Another wave traveling along the front well to our south may push some clouds or precip back into the far southeast part of the area late Sunday night. The NAM was more aggressive than the GFS with this, and confidence is low that any showers will materialize this far north. Have only used a 20-30 percent in our far southeast counties. .LONG TERM...(Monday through Saturday) Issued at 458 PM EST SAT FEB 24 2018 Overall have a bit lower confidence in the extended portion of the forecast than usual, mainly due to unusually inconsistent ECMWF runs. In general our area remains under the influence of southwest flow at the surface and aloft, at least until late in the week. Short wave trough does move through the region at the beginning of the period, reflecting a sfc wave of low pressure that skirts just to our south and east Monday. Thereafter models depict southern stream energy moving out of the deep southwest and phasing with northern stream energy over the Midwest or Great Lakes by late Thursday or Thursday night. A quick peak at the 12Z ECMWF shows a strong move towards the GFS solution as compared to the 0Z run. As often seems to be the case the Canadian takes the middle ground, measuring up right in between the GFS and ECMWF, at least until the 12Z European came out. At the surface a deepening surface low spins up rapidly as it pushes through the Ohio Valley and Great Lakes Thursday-Thursday night. A cold or occluded frontal boundary swings rapidly through the Commonwealth Thursday. All models build a ridge back into the Ohio Valley at the end of the forecast window. Sensible weather features a chance for some additional shower activity early Monday morning as a disturbance tracks across the southern Appalachians. Trends seem to be towards drier weather, with scattered showers being restricted to the far south-southeast. Surface high pressure then exerts itself keeping our weather dry until mid week. Rapidly developing storm system will bring widespread rain back to our area by Wednesday as it deepens over the mid Mississippi Valley region. This potent storm system sweeps a frontal boundary through the area Thursday. Showers will linger well behind the front as wrap around moisture is pulled into eastern Kentucky from the Great Lakes and upslope showers take form Thursday night into Friday. Weather improves for the end of the forecast window as high pressure builds back into the region, both at the surface and aloft. Daily high temperatures remain above normal, in the mid to lower 60s through Thursday, then drop back to normal levels by Friday and Saturday, lower 50s. Overnight lows start out near normal, mid 30s, Tuesday morning before climbing into the 40s to near 50 for the latter half of the week. Lows finally manage to drop to to normal levels as well, lower 30s, by Saturday morning. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) ISSUED AT 735 PM EST SAT FEB 24 2018 VFR was initially in place across the region, with the exception of SYM and portions of northeast KY along and north of a warm front lifting north. Isolated showers are traversing the region, but showers and some thunderstorms are expected to approach from the west between 2Z and 5Z as a cold front approaches. These should affect the western sties just as SYM, SME, and LOZ primarily between 5Z and 11Z and eastern sites of SJS and JKL mainly between 7Z and 12Z. Vis and or CIGS should be down into the MVFR if not the IFR range at times during heavier showers and along and immediately behind the cold front. The convection will then exit to the southeast, with VFR conditions returning along with slackening winds between 12Z and 18Z. Winds will be gusty as the front nears initially out of the south at 5 to 10 KT, but increasing to the 10 to 15KT range in most locations by 3Z with gusts of 20 to 30KT possible. Higher gusts may occur in thunderstorms. Winds should shift to the southwest and then west as the front moves form west to east during the 7Z to 14Z period. && .JKL WATCHES/WARNINGS/ADVISORIES... Flood Watch until 7 AM EST Sunday for KYZ044-050>052. && $$ UPDATE...JP SHORT TERM...HAL LONG TERM...RAY AVIATION...JP
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
540 PM CST Sat Feb 24 2018 .SHORT TERM... (Through Late Sunday Afternoon) Issued at 253 PM CST Sat Feb 24 2018 Main concerns continue to be flooding and severe weather threats through the evening. Latest round of showers with embedded thunderstorms has already overspread the CWA with additional moderate to heavy rainfall. This will bring the threat for potential flooding into the evening hours over the watch area which as already seen significant rainfall this week. Will also continue to monitor the potential for few strong to severe thunderstorms across southwest Missouri into south central Illinois late this afternoon and early this evening. RAP runs have been consistent today in showing a weak surface low along the triple point moving northeast from near Farmington to Effingham. While low level instability is weak, low level and deep level shear will be more than sufficient to allow for a few severe thunderstorms. The main threat will be damaging winds, but cannot rule out a tornado threat. The front will move east of the area this evening, and there will be some gusty west to northwest winds behind late evening into the overnight hours as the pressure gradient will be fairly tight as the main surface low moves across Missouri into northern Illinois. The winds will decrease by Sunday morning as this low exits into the Great Lakes. Sunday is expected to be dry with sunshine as subsidence sets in as the upper trough moves off to the east. There is not any notable cold air moving in behind this system, so temperatures will climb back above normal on Sunday. Britt .LONG TERM... (Sunday Night through Next Saturday) Issued at 253 PM CST Sat Feb 24 2018 Dry weather is expected to last into Monday and Tuesday as a large surface high moves across Missouri and Illinois. The chances for rain will increase by the middle of next week as the GFS/ECMWF both show a deep trough moving into the central CONUS with a surface cold front moving across Missouri and Illinois Wednesday/Wednesday night. This trough should draw Gulf moisture northward ahead of it, and have added a chance of thunderstorms ahead of the the front. Temperatures ahead of the system on Tuesday and Wednesday should be well above normal, though they are expected to stay above normal even behind the system late week. Britt && .AVIATION... (For the 00z TAFs through 00z Sunday Evening) Issued at 524 PM CST Sat Feb 24 2018 Low ceilings and visibilities will be found over the area through this evening before conditions improve to VFR everywhere after 06Z. Rain will also move out of the area this evening. Winds will turn out of west this evening and be gusty before decreasing early on Sunday. SPECIFICS FOR KSTL: Ceilings and visibilities will improve during the evening, and will turn VFR after 06Z. Scattered showers also may affect the terminal this evening, but dry weather is also expected after 06z. Westerly winds will be gusty at times tonight, but will decrease after 10Z. Britt && .LSX WATCHES/WARNINGS/ADVISORIES... MO...Flood Watch until midnight CST tonight for Crawford MO-Franklin MO-Gasconade MO-Iron MO-Jefferson MO-Madison MO-Osage MO- Reynolds MO-Saint Charles MO-Saint Francois MO-Saint Louis City MO-Saint Louis MO-Sainte Genevieve MO-Warren MO- Washington MO. IL...Flood Watch until midnight CST tonight for Bond IL-Clinton IL- Fayette IL-Madison IL-Marion IL-Monroe IL-Randolph IL-Saint Clair IL-Washington IL. && $$ WFO LSX
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
918 PM CST Sat Feb 24 2018 .UPDATE... Issued at 915 PM CST Sat Feb 24 2018 Started moving up expiration times of winter headlines a few hours to more closely coincide with when the snow will end. Forecast soundings show mixing and gust potential being fairly limited overnight, so not expecting significant blowing and drifting snow concerns, hence ending the headlines closer to when the snowfall is forecast to end. && .SHORT TERM...(This evening through Sunday) Issued at 326 PM CST Sat Feb 24 2018 Heavy snow is filling in rapidly across Minnesota, but one can already see the back edge in the vicinity of Sioux Falls and Brookings, SD. This clearing will make steady progress northeastward through the evening hours, reaching western MN early this evening, eastern MN late this evening, and western Wisconsin shortly after midnight. Until that point, widespread expect heavy snow to continue with 1 to 2 inch per hour rates. Radar reflectivity is looking more convective across southern Minnesota, which continues to lead to very high confidence in the longevity of the intense snow rates. Still thinking there is some chance of thundersnow across east central MN and western WI. The snow outside of our office is pretty grainy as of 315 PM. This may transition to pure dendrites, or it may remain a bit more sleety into the evening. This could reduce the snow ratios some, but hi-res models have increased the amount of QPF over the last few runs so it may end up a wash in terms of final totals. Wind will increase behind the snow overnight, leading to some blowing and drifting. Forecast soundings are pretty impressive with wind aloft, but the gusts are tempered by less than ideal cold air advection/steep low level lapse rates. This should prevent blizzard conditions from developing, but it will need to be watched this evening. .LONG TERM...(Sunday night through Saturday) Issued at 326 PM CST Sat Feb 24 2018 The long term will commence with a slight incoming ridge aloft in advance of a weak surface frontal system. The main surface low will shift east while remaining north of the international border, dragging its cold front through the region Monday night. Relatively little moisture along with NVA will accompany the frontal passage, resulting in nothing more than an increase in cloud cover. The surface front will then settle to the south of the region, extending southwest from the Great Lakes through Iowa into CO/KS, by Tuesday morning. While this occurs, a very potent upper level trough will drop south along the western CONUS coast, with the trough aiding cyclogenesis over the TX/OK Panhandles. Surface high pressure will then slide across the region Tuesday and Tuesday night, washing out over the eastern Great Lakes and not having much of an influence to move the stalled front away from the area. The surface low over the Panhandles will then shift northeast along the stalled front Wednesday-Thursday, being nudged along by the sharp longwave trough over the southwestern CONUS. As this system moves northeast, a mixture of both Pacific and Deep South moisture again look to converge over the Upper Midwest, available for this incoming system to tap and effectively produce precipitation across much, if not all of, the WFO MPX coverage area. The main issue then becomes temperatures, as warmer air in advance of the system may make for a mixture of rain/snow instead of solely snow. The upper low pivots over the Central Plains on its way to the Great Lakes Wednesday night through Thursday, bringing the system out of the area by Thursday night, followed by surface high pressure and upper level ridging for Friday. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 553 PM CST Sat Feb 24 2018 Not many changes to going TAFs when it comes to the current snowfall. Back edge of the snow is already in SW MN and will quickly shift north and east this evening. Like Thursday night, the big question with this system is how quickly do skies clear out behind the snow. Looking at satellite and upstream obs, we may loose the sub VFR cigs a couple of hours after the snow shuts off, with more sun than clouds expected tomorrow. Clouds will hang on longest north of I-94. For cigs going to VFR, trended the timing toward a blend of the fast RAP and slower LAV. For winds, as the inverted trough swings through, there will be a rapid nearly 180 degree switch in directions from the east over to the west. Also, we could see some wind gusts in MN up around 30 kts for the first couple of hours post shift, but they should settle down to 20-25 kt gusts that will persist through Sunday. KMSP...Heavy snow with 1/2sm and 1/4sm vis will dominate the first 3 hours of this TAF, but rapid improvements are still expected after 3z, with the snow done by 6z. Lower confidence on cig trends in the morning, but we should be mostly VFR by 16z, though could happen much earlier than that. /OUTLOOK FOR KMSP/ Mon...VFR. Wind SW at 10-15kt. Tue...VFR. Wind N at 5 kts. Wed...MVFR with SN possible late. Wind E at 5 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...Winter Storm Warning until 3 AM CST Sunday for WIZ023-024-026. Winter Storm Warning until 4 AM CST Sunday for WIZ014>016-025- 027. Winter Weather Advisory until 4 AM CST Sunday for WIZ028. MN...Winter Storm Warning until 3 AM CST Sunday for MNZ050-051- 058>063-066>070-076>078-084-085. Winter Weather Advisory until 3 AM CST Sunday for MNZ041>043-048- 049-057. Winter Storm Warning until 4 AM CST Sunday for MNZ044-045-052- 053. Winter Storm Warning until 10 PM CST this evening for MNZ065- 073>075-082-083-091-092. Winter Weather Advisory until 1 AM CST Sunday for MNZ093. && $$ UPDATE...MPG SHORT TERM...BORGHOFF LONG TERM...JPC AVIATION...MPG
Area Forecast Discussion
National Weather Service San Francisco Bay Area
742 PM PST Sat Feb 24 2018 .SYNOPSIS...Partly cloudy skies with scattered showers across the North Bay this afternoon. Otherwise, some clearing is expected tonight with chilly low temps. Dry weather and slightly warmer temperatures are expected through the weekend. Cooler and unsettled weather is expected to return by early next week with another system bringing rain to the area later next week. && of 01:50 PM PST Saturday...A little afternoon excitement as a few showers popped up over the North Bay. Spotters/general public reported a few showers near Santa Rosa, Healdsburg and Windsor. For what it`s worth, local WRF and HRRR kept showers off the coast this afternoon. That definitely didn`t pan out and therefore updated forecast to better reflect reality. Do expect this showers to gradually dissipate over the next hour or so. No frost or freeze headline needed for tonight. A slight increase in cloud cover will limited cooling potential. Temps tonight are forecast to be a few warmer than last night. That being said, overnight lows will still be rather chilly and in the upper 20s to mid 30s for most locations. Bay Shoreline and coast in the low 40s for lows. Weak ridging ahead of the next storm system will allow for warmer weather on Sunday. In fact, it could be some of the warmest temps of the last several days with highs hitting 60 plus across the interior. By Sunday night the next system approaching from the north will begin to impact the Bay Area. Showers will move in from N to S and likely impact the Monday morning commute. Snow levels will initially be greater than 3k feet, but then gradually drop through the day. Winter precip will be possible over the higher peaks of the forecast area, similar to earlier this week. Precip will end from NW to SE Monday night into Tuesday. Rainfall amounts are still generally low and mainly a few hundredths to a few tenths. Dry weather returns briefly on Tuesday with a slight warm up, but the next storm is waiting in the wings. For several model runs (deterministic/ensemble) now a potent low pressure has been forecast to impact the Pac NW Wednesday into Thursday. The associated cold front is also forecast to move into NorCal by Thursday morning. The front pushes through the Bay Area Thursday with post frontal showers lingering well into Friday. Not an atmospheric river event per se, but a better moisture tap than we have seen over the last week. Rainfall amounts could exceed an inch across the North Bay and one quarter to one half elsewhere. Details will likely be sorted out between now and then, but initial thinking is a wetter scenario. It should be noted that this set up will be warmer with higher snow levels and initially impacting only the Santa Lucias. The snow levels will drop behind the front. Lastly, the MJO has been on track to swing into Phase 2/3, albeit weak, for some time now. Climo charts for Phase 2/3 indicate wetter results for CA. The shift to Phase 2/3 corresponds with Feb 28/March 01 time frame, which fits the approaching front on the medium range models. && of 7:39 PM PST Saturday...VFR. There is more water vapor in the near surface to lower atmosphere this evening compared to yesterday at this time, double digit dewpoint temperature recovery, thus areas MVFR cigs are possible overnight; best chance for MVFR cigs per WRF model boundary layer output is from the South Bay to the north Central Coast. Boundary layer drying tends to settle back in on W-NW flow over the remaining Bay Area overnight and Sunday morning. A quickly moving, elevated, and mainly dry cold front swept southward over the area today. Cold air advection was mostly located in the lower levels 925 mb to 850 mb, gusty surface to lower level W-NW winds will diminish this evening per decreasing instability, mixing within the boundary layer. The 00z temperature profile on this evening`s 00z Oakland upper air sounding looks almost identical to last evening`s, but the big difference is the increase in water vapor below the subsidence inversion. High pressure reaches into the Great Basin temporarily reversing the SFO-WMC pressure gradient to weak offshore and flattening the SFO-SAC gradient tonight into Sunday morning. A low pressure system arrives from the north late Sunday and Monday. Vicinity of KSFO...5 minute wind observations still show winds westerly gusting to 20-25 knots. As inherited taf indicates, winds should begin to subside below 20 knots by 04z or so. Winds continue to subside tonight, possibly becoming light N-NE early Sunday morning. SFO Bridge Approach...Similar to KSFO. Monterey Bay Terminals...VFR. Onshore winds will gradually dissipate and become E-SE 5-10 knots late tonight and Sunday morning. && .CLIMATE... A few locations may be near record low temperatures Sunday morning and possibly Tuesday morning next week. Temperatures will be mainly below late February normals through early next week, but increasing clouds, showers, and breezy winds with a low pressure system arriving later Sunday into Monday should help keep lows above records on Monday. Location Sunday Tuesday SF Bay Area Healdsburg 29 in 1920 25 in 1962 Santa Rosa 24 in 1915 24 in 1962 Calistoga 29 in 1966 24 in 2012 Kentfield 29 in 1920 26 in 1962 San Rafael 26 in 1904 29 in 1962 Napa 30 in 1962 28 in 2011 San Francisco 38 in 1887 38 in 1962 SFO Airport 35 in 1953 32 in 1951 Half Moon Bay 33 in 1996 31 in 2011 Oakland Airport 33 in 1953 31 in 1962 Richmond 36 in 1962 34 in 1962 Livermore 28 in 1942 25 in 1962 Moffett Field 34 in 1953 30 in 1962 San Jose 28 in 1894 28 in 1893 Gilroy 31 in 1965 24 in 1962 Monterey Bay Area Santa Cruz 30 in 1911 25 in 1962 Salinas 32 in 1997 25 in 1962 Salinas Airport 25 in 1935 29 in 1962 Monterey 35 in 1956 27 in 1962 King City 23 in 1974 23 in 1962 && of 5:49 PM PST Saturday...Gusty nw winds will continue overnight into Sunday as a dry cool front moves through and high pressure builds. Another strong cold front drops down the coast on Monday with some showers and gusty nw winds behind the front into Tuesday. && .MTR WATCHES/WARNINGS/ADVISORIES... .Tngt...SCA...Pigeon Pt to Pt Pinos 0-10 nm SCA...Pt Arena to Pigeon Pt 10-60 nm SCA...Pt Arena to Pt Reyes 0-10 nm SCA...Pt Reyes to Pigeon Pt 0-10 nm SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm SCA...Mry Bay until 9 PM && $$ PUBLIC FORECAST: MM AVIATION: Canepa MARINE: RWW Visit us at Follow us on Facebook, Twitter, and YouTube at:
Area Forecast Discussion
National Weather Service Omaha/Valley NE
519 PM CST Sat Feb 24 2018 .SHORT TERM...(Tonight through Tuesday) Issued at 320 PM CST Sat Feb 24 2018 The main forecast concerns in this period are precipitation ending this evening, temperatures through the period and increasing levels of fire danger by Monday in parts of southeast NE. Shortwave trough was to our west at 12Z and 500 mb chart showed height falls of 50 to 110 meters from eastern NE back to WY, CO and NM with a max HFC over Albuquerque. GOES 16 water vapor loop early this afternoon showed that the main vort max had lifted up into central SD with a dry slot over our area. We were still getting some pockets of light snow with RAP forecast soundings showing some steeper mid level lapse rates. Precipitation will be ending from west to east late this afternoon and evening. Will clear out the winter weather advisory from west to east. Otherwise, look for decreasing cloudiness tonight. There could be some patchy fog but with a westerly low level flow thought it was OK to leave out of the forecast for now. Some high level clouds will try to work their way back into the southern parts of the forecast area late tonight and should continue into Sunday. Highs Sunday will not be as cold as today, reaching 35 to 40 north and lower to mid 40s south. Increasing southerly flow will bring in warmer air for Monday, with highs ranging from 40s north to 50s south. Winds should also increase into the 15 to 20 mph range with gusts 25 to 30 mph. This may push fire danger toward the very high category in parts of southeast NE Monday afternoon. A cold front will slide down into the area from the north for Tuesday. There are some hints (mainly from the NAM) of maybe some light precipitation, but did not include that at this time. .LONG TERM...(Tuesday night through Saturday) Issued at 320 PM CST Sat Feb 24 2018 Some of this period will be more active, mainly from Tuesday night through Wednesday night. The shortwave trough currently over the Gulf of Alaska will drop southeast through Tuesday. By 00z Wednesday, this should split into a northern stream wave and a southern stream wave. A closed low is forecast to drop down into southern CA, AZ and NM Tuesday night. On Wednesday, that will then lift toward central KS while the northern stream wave somewhat phases in with the ejecting southern stream system. Models are fair agreement that that system will then intensify, with a closed low somewhere over southern IA by 12z Thursday. The 12z ECMWF has trended toward the GFS solution and the ECMWF is now much wetter, especially from southern MN into IA and MO. Will keep chance to likely POPs going Wednesday into Wednesday evening. Expect enough of a temperature range for snow north and rain south. Late in the week, a mid tropospheric ridge is expected to build over the central part of the nation with highs trending back toward 40s and 50s by Saturday. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 514 PM CST Sat Feb 24 2018 The stratus are breaking up now that the storm system is exiting the area. Look for a few clouds to linger for the first couple of hours with some patchy MVFR conditions. The westerly flow will increase and added low level wind shear for varying amounts of time between 03-11Z. Some patchy fog will try to develop toward morning due to the wet ground, however with the winds aloft, think it will be patchy enough to hold off much of a mention for now. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ SHORT TERM...Miller LONG TERM...Miller AVIATION...Zapotocny
Area Forecast Discussion
National Weather Service Charleston WV
906 PM EST Sat Feb 24 2018 .SYNOPSIS... Warm front pushes north through the area tonight. Cold front sweeps across Sunday. High pressure brings dry air by Sunday and start to work week. Next low pressure system mid week. && .NEAR TERM /THROUGH SUNDAY/... As of 350 PM Saturday... Sent an update to remove most PoPs across the lowlands in a lull suggested by the HRRR and latest radar images. Another but more widespread area of rainfall is evident moving northeast across central KY into southern OH. This activity is expected to reach southeast OH by 00Z Sunday. Rest of forecast remains on track. As of 120 PM Saturday... Warm advection rainfall did finally pick up in intensity, causing some small stream and poor drainage flooding. This rain will move out of the area by this evening, but more rounds are expected later tonight. As of 1045 AM Saturday... Rain overnight did not amount to much, and neither is warm advection rain today so far. Mainstem Ohio river forecasts reflect lower crests, as a result. The weather forecast is otherwise largely on track. As of 300 AM Saturday... A frontal boundary will remain across the area today as a wave brings an area of showers. Much of the area should then go into a lull later this afternoon and early this evening as the front pushes north of the area. Showers will return later tonight as a cold front approaches from the west. Models continue to show the highest rainfall amounts over southeastern Ohio and northern West Virginia, although amounts are toned down compared to previous runs. Will continue the flood watch as the ground is saturated and streams and rivers continue to run high. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... As of 140 PM Saturday... Wave developing along the front on the south and east side of the mountains could push some light rain back into the southwest Virginia and far southern West Virginia counties Sunday night/early Monday morning, but will quickly be forced back out of the southern zones of the CWA. Otherwise, the period is dominated by high pressure and a much welcomed drying out period. Dominant upper level ridging over the Gulf of Mexico and Florida keeps the area milder than normal for this time of year with above 0C 850mb temperatures. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... As of 140 PM Saturday... More rain arrives for the middle to end of the week from a fast moving panhandle low pressure system. Will need to watch the rainfall amounts combined with the ability for the rivers/creeks/streams/surface to recover from a very wet second half of February, and if the system will set up over the Ohio Valley yet again. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... As of 700 PM Saturday... A warm front pushes north across the OH and WV tonight. Rain showers will spread slowly from west to east through the overnight hours. Widespread MVFR/IFR conditions expected especially along moderate to heavy rain. Cloudiness and southerly boundary layer winds around 15 to 20 knots will keep radiational fog from development. However, warm moisture advection could produce periods of dense fog under LIFR ceilings. Improving conditions are expected by mid morning 15Z. However, periods of IFR/MVFR conditions will continue under areas of moderate to heavy rain and low clouds Sunday. A cold front will quickly cross the area late Sunday morning to early Sunday afternoon. Gusty showers will be common along the front with a wind shift to the west to southwest, and brief MVFR to IFR conditions. Models show LLWS possible mainly across the northern sites with H850 winds of around 50 knots mixing down to below 2000 feet to about 30 knots. If sfc winds become calm overnight, LLWS will pose a threat. Therefore, will include LLWS at PKB, EKN, and CRW for now expecting light to moderate sfc winds at BKW, CKB and HTS overnight after 09Z. Conditions could become VFR/MVFR behind the front with a quick improvement to VFR Sunday afternoon. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z MONDAY... FORECAST CONFIDENCE: Low to medium. ALTERNATE SCENARIOS: Timing and intensity of restrictions will vary, as will gusty winds. LLWS could not develop if sfc winds remain moderate. 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 L M M M M M M M M M L L HTS CONSISTENCY M M M M H H H H H H L L BKW CONSISTENCY H H M H H H H H H H M M EKN CONSISTENCY H M M M M H H H M H L L PKB CONSISTENCY L L L L L L H M M M L L CKB CONSISTENCY M M M M H H H M H H L L AFTER 00Z MONDAY... IFR possible in dense fog Monday and Tuesday mornings, and in rain Wednesday night into Thursday. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...Flood Watch through Sunday afternoon for WVZ005>011. OH...Flood Watch through Sunday afternoon for OHZ066-067-075-076- 083>087. KY...Flood Watch through Sunday afternoon for KYZ101>103-105. VA...None. && $$ SYNOPSIS...TRM/26 NEAR TERM...ARJ/TRM SHORT TERM...26 LONG TERM...26 AVIATION...ARJ
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