Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/18/19

National Weather Service Wakefield VA
927 PM EDT Fri May 17 2019 .SYNOPSIS... A trough of low pressure crosses the area late this evening, with a backdoor cold front dropping south into southern Virginia and northeast North Carolina on Saturday. The boundary lifts back north as a warm front Saturday night into Sunday as high pressure becomes anchored off the southeast and mid Atlantic coast through early next week. The next cold front crosses the region Monday night. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... As of 925 pm EDT Friday... Isolated to widely sct showers continuing to fire NW of Richmond along and just south of I-64. Locally heavy rainfall is the primary concern at this point, but a few stronger (sub-svr) wind gusts and small hail possible. Majority of convective potential lies to the west with developing MCS dropping across WV and far W VA. Threat will continue to steadily taper off as MCS decays overnight, but will hang on to shower chance into the early morning hours late tonight, with showers clearing out late. Previous discussion... As of 350 PM EDT Friday... Latest analysis indicating WNW flow aloft, with a weak sfc trough over the region. Earlier clouds from the morning decaying MCS have scattered out. Thus far, nothing developing on the radar, though an area of BKN cloud cover has developed over south central VA. Models continue to differ with respect to timing and the strength of the next projected shortwave energy aloft into early this evening, but the overall theme remains unchanged in that a synoptic NW flow aloft is often a signal for strong to severe tstms this time of year provided that adequate instability is present. The CAMs also show conflicting coverage of tstms into this evening, with the HRRR generally only suggesting about a 20-30% coverage, while the NAM and the ARW is a little more robust. SPC Day 1 outlook continues to have areas from FVX to RIC to the northern Neck in a slight risk (mainly due to effective shear to around 40 kt) with a bordering area of marginal risk for southern VA (where shear is a little lower to 30-35 kt). The primary risk is highest for damaging wind gusts but won`t rule out some large hail as well. (a little cooler on the eastern shore). Will have highest PoPs (still capped in the 30-40% range) from 21Z- 00Z over the NW, then transitioning through the heart of the CWA during the evening. The highest severe threat will be through around 02Z, with less of a threat thereafter. Convection will slowly weaken later this evening and overnight as the shortwave moves east. A weak/backdoor cold front is then progged to sag S across the local area overnight switching the winds to the NE (especially along the coast). Partly/mostly cloudy skies this evening become partly cloudy after midnight. Warm with lows mostly in the lower to mid 60s. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/... As of 350 PM EDT Friday... Models show the front washing out over the area Sat before lifting back north as a warm front by Sat night/Sun. Low level flow becomes onshore near the coast Sat with a weak pressure gradient as high pressure becoming centered off the mid Atlc coast. Data rather sporadic wrt the amount of moisture, but did keep ~20% PoPs across portions of the SE inland from the coast (given wind convergence ivof the boundaries) and nw Piedmont (ivof the advancing warm front wrt convection drifting se from off the Blue ridge). Winds shift back to the SSE allows for the summer heat to overspread areas west of the bay. Skies pt sunny with highs mid/upper 80s (around 90 F far SW) west of the bay but lingering onshore flow (lcl sea- breezes) keep areas near the water in the mid 70s-lwr 80s. Slight chc to chc PoPs Sat night across the north ivof the northward lifting warm front. Lows in the 60s. Sunday appears to be the hottest day as the warm front finally lifts north of the local area with the Bermuda ridge taking control. Any PoPs limited to the extreme nrn zones. Highs in the upr 80s/around 90f except 80-85 F along the coast. Mostly clear Sun night with lows in the 60s, then partly/mostly sunny again Mon with highs into the upper 80s/around 90F most areas (just as warm at the coast due to a stronger SW wind). && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... As of 330 PM EDT Friday... Upper-level ridge will remain centered over the SE states throughout next week. The Mid-Atlantic will be on the edge of the ridge with a few frontal system moving across the area. There`s more confidence that the southern VA Piedmont will remain hot and dry throughout the extended with highs in the low to mid 90s and lows in the upper 60s. A cold front will move through Monday night into early Tuesday morning. Slight chance of Pops and isolated tstrm with the front (20- 30%) on Tuesday morning east of I-95. Temperatures will be cooler with highs in the mid 80s along I-64 and 70s at the beaches and MD eastern shore. The heat will begin to build back northeast Wednesday. GFS has the ridge building back north earlier on Wednesday than most guidance. With 850 mb temps rising to 16-19C and with downsloping, highs may get to the upper 80s to near 90 west of Richmond. With a onshore flow at the surface temps will remain in the 70s at the beaches and eastern shore. Thursday and Friday the ridge will amplify over that area with hot and mostly dry conditions. Highs will reach in the low 90s inland and mid 80s at the beaches. Shortwaves will be moving along the edge of the ridge just to the north of the area. That may bring showers/tstms to the MD eastern shore. && .AVIATION /01Z SATURDAY THROUGH WEDNESDAY/... As of 925 PM EDT Friday... VFR conditions across area terminals, with isolated to scattered showers/tstms in the vicinity of KRIC from 02Z through 04Z inland, shifting to the coast (PHF-ORF) from 04-06Z. Not enough coverage to go with prevailing showers or tstms at any of the main terminals. Generally drying out after midnight, with winds shifting to the NNE towards 12Z/Sat morning. There could be a few hrs worth of low clouds/patchy fog early Sat but that will be dependent upon where the rain falls tonight so did not include in the TAFs. Otherwise, VFR with NE winds up to 10 kt on Sat and mainly dry conditions. An isolated shower/tstm possible by late Sat aftn. Outlook: The weak frontal boundary lifts back north as a warm front Sat night into Sun, with some isolated to widely scattered showers and tstms Sat night. Sun will generally see winds turning more to the SSW inland and to the SSE along the coast with mainly VFR conditions. A little bit stronger SW wind for Mon with late day tstms possible. && .MARINE... As of 345 PM EDT Friday... Surface high pressure off the Southeast coast will continue to produce SSW winds 5-15 knots over the marine area through this evening. Waves 1-2 ft; seas 2-3 ft. A cold front will drop south across the waters from late tonight into Saturday morning, turning winds to the N and NE by Saturday morning, then eventually E and SE Saturday afternoon as the front continues south. The front then returns north and east on Sunday as a warm front, with winds veering to the SSE. The pressure gradient will tighten a bit late Sunday and into Monday with south/southwest winds increasing to 10-15 knots, with 15-20 knots possible offshore for a brief time Monday evening. Another low passing to the north Tuesday morning will send a cold front southeastward, allowing winds to become northwesterly 10-15 knots, then becoming NE in the afternoon. Waves in the bay will generally run 1-2 ft and seas 2-4 ft through the period. As of now, sub-SCA conditions are expected through the middle of next week. && .TIDES/COASTAL FLOODING... Water levels on the Bayside of the lower MD Eastern Shore (specifically around Bishops Head) will continue to run above normal with the next high tide cycle tonight. Water levels may touch or just exceed minor flooding thresholds at Bishops head. Therefore, a Coastal Flood Statement has been issued. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...None. && $$ SYNOPSIS...LKB NEAR TERM...LKB/MAM SHORT TERM...LKB LONG TERM...CP AVIATION...LKB MARINE...JDM TIDES/COASTAL FLOODING...
Area Forecast Discussion
National Weather Service La Crosse WI
643 PM CDT Fri May 17 2019 .SHORT TERM...(This evening through Saturday) Issued at 308 PM CDT Fri May 17 2019 Main impactful weather concerns through Saturday are on the potential for periods of heavy rainfall, which could lead to some flooding, and the possibility for a few storms capable of producing large hail and maybe gusty winds. This activity arrives in a few rounds, potentially three. Round 1: A trough lifts into the Upper Midwest tonight pushing an elevated warm front north into the forecast area. This front will be the focus for thunderstorms development and the potential for heavy rain and localized flooding. Latest convective allowing models suggest thunderstorms get going along the elevated warm front in the 5 to 8 Z timeframe over southeast Minnesota into west central Wisconsin. This activity should continue to increase and potentially drift north as 850 mb moisture transport focuses into the front. With ongoing convection along this front, it may be difficult for the front to make northward progress, increasing the potential for repeated rounds of rain and possible flooding. Will have to monitor the evolution and movement of the thunderstorms activity closely tonight. Round 2: A line of storms looks to move across the area from west to east Saturday morning. Latest HRRR models show the line moving into southeast Minnesota and northeast Iowa by 12 Z then progressing eastward through the morning, moving into western Wisconsin around 13Z then finally exiting the forecast area by 16Z. These storms appear to riding on the leading edge of the strongest 850 mb moisture transport, so the HRRR model solutions make sense. These storms will likely produce a quick round of heavy rainfall but the heavy rain environment isn`t overly impressive with warm cloud depth of around 3.5 km and precipitable water values of 1.2 to 1.4. But this rain on top of saturated soils may cause additional localized flooding, following any potentially heavy rainfall from Friday night into early Saturday morning. This line of storms may also produce some large hail with the RAP indicating elevated CAPE values approaching 1300 J/kg when lifting from 850 mb. Round 3: We should then see a brief break in the activity between mid morning and early afternoon before more thunderstorms develop in the 3 to 4 pm timeframe as the main trough starts to lift north out of the Central Plains. Will have to keep a very close eye on the position of the warm front and tipple point as the surface low moves into northeast Iowa. There is a window for surface based storms over northeast Iowa Saturday afternoon with the potential for a Supercell or two. Also, north of the front there is the possibility for elevated storms capable of producing large hail. If surface bases storms develop, main potential for this will be over northeast Iowa, there could be a window for an isolated tornado however 0-1 km Shear isn`t overly strong, 15 to perhaps 25 kts closer to the warm front. Convection then becomes widespread by late afternoon into Saturday evening as the trough continues to lift north producing broad lift across the area. The threat then transitions over to heavy rainfall Saturday evening into the overnight. With saturated ground and potentially higher rainfall rates, there could be flash flooding concerns starting Saturday afternoon and continuing into Saturday night. A Flood Watch may be needed from Saturday afternoon through Saturday night. Rain then tapers off during the day on Sunday as the low lifts off to the northeast. If the GFS solution holds, there could be another shot at strong to severe storms Sunday afternoon as the surface low lifts northeast across the area, but confidence is low on this. .LONG TERM...(Saturday night through Friday) Issued at 308 PM CDT Fri May 17 2019 Focus in the long term turns to thunderstorm chances Tuesday into Tuesday night. Another vigorous low pressure system lifts northeast out of the Central Plains Tuesday into Tuesday night. Depending on the timing of this system through the region, there is the potential for strong to severe storms. Confidence is too low at this point to nail down details on potential storm threats. The active pattern will continue through the end of next week as southwest flow aloft continues across the region. The next potential round of showers and storms could impact the area Thursday into Friday. The good news is that temperatures look to warm a bit for the last half of next week with highs in the upper 60s to lower 70s Wednesday, possibly warming into the low to mid 70s by Friday. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 643 PM CDT Fri May 17 2019 An axis of showers and thunderstorms will continue to develop and lift north through the region this evening and overnight, impacting LSE and RST through roughly 06Z before lifting sufficiently far north to end any thunder risk. Another line of showers and storms is then expected to arrive from the west roughly in the 12-15Z time range Saturday morning, with another break following into the afternoon, before yet more widespread rain and storms redevelop through the late afternoon and evening hours. Overall, conditions will remain MVFR at RST and primarily VFR at LSE through the evening, but should briefly improve for many areas to VFR overnight as drier air works in from the east. However, a return to MVFR or even IFR ceilings is likely through the day Saturday, with even some hints that widespread IFR conditions will envelop the entire area, north of a warm front stuck just to our south. Will have to monitor conditions closely to see if that develops, but overall, looking like a very active stretch of weather the next 24-36 hours, with winds pretty much steady-state from the southeast 8-15 knots through midday Saturday before gradually diminishing later in the day. && .HYDROLOGY...Through Sunday. Issued at 308 PM CDT Fri May 17 2019 Several rounds of showers and thunderstorms will impact the area mainly tonight through Sunday night. The heaviest rain is expected Saturday afternoon into Saturday night. If thunderstorms repeat over areas, flash flooding could develop. Rainfall totals of 2 to 3 inches are possible. River flooding will also become a growing concern. Will continue with a hydrologic outlook for much of the area, but confidence is increasing that a flood watch may be needed from Saturday afternoon into Saturday night. Those living in areas prone to flooding, especially along rivers and streams, should be prepared to move to higher ground if heavy rainfall develops. Continue to monitor forecasts closely. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ SHORT TERM...Wetenkamp LONG TERM...Wetenkamp AVIATION...Lawrence HYDROLOGY...Wetenkamp
Area Forecast Discussion
National Weather Service Cheyenne WY
934 PM MDT Fri May 17 2019 .UPDATE... Issued at 927 PM MDT Fri May 17 2019 Showers should continue to decrease during the remainder of the evening into the overnight. Could still see a few showers develop along the northern sections of the forecast area as a mid level trof moves into that region. Otherwise, most areas should begin to dry out overnight as the isentropic lift weakens. UPDATE Issued at 715 PM MDT Fri May 17 2019 Latest mesoanalysis was showing the bulk of the instability east in central Nebraska with limited convective development in northern Colorado. As a result, we have decided to cancel the Severe Thunderstorm Watch in the southern Nebraska panhandle. UPDATE Issued at 537 PM MDT Fri May 17 2019 Currently issuing warnings on the cluster of storms moving northeast through Cheyenne county Nebraska...with large hail being the primary threat. We were able to bring down Severe Thunderstorm Watch 171 for Scottsbluff and Banner counties as MUCAPES and SBCAPES remain low due to cloudcover and rain, however the Sidney NE area remains unstable enough to sustain strong updrafts and hail potential...and elevated storms could persist with large hail up into southeastern Morrill county. Severe Thunderstorm Watch 171 continues for Kimball, Cheyenne and Morrill counties. && .SHORT TERM...(Today and Saturday) Issued at 215 AM MDT Fri May 17 2019 .Strong to Severe Thunderstorms Expected Today... Morning objective analysis showed a classic post frontal upslope flow regime across far northern Colorado, southeastern Wyoming, and western Nebraska. The wavy front was analyzed near the Colorado Nebraska kansas border along with an attendant 998 mb surface cyclone and a southward developing dryline. Rich boundary layer moisture, with dewpoints in the middle 50s, was pooled along and north of the front. Mid 60s dewpoints were located further south and east across the warm sector. Morning satellite showed the beginnings of a low stratus deck taking shape across the panhandle in response to upslope moistening. Surface pressure falls near 0.3 mb/hour have been noted, and will continue this morning as the lee low gradually lifts north and east along the front in response to downstream DPVA from the large west coast trough moving onshore. This will set the stage for severe thunderstorms this afternoon and evening. High resolution guidance continues to paint an interesting picture this afternoon and evening as the lee low and front begin to move to the north and east. The rich moisture in place will underlay steep midlevel lapse rates near 8 c/km from the cold upper trough. This will allow sufficient destabilization to shape up this afternoon. SBCAPE of 1000-1500 j/kg is likely along the front and through the southern panhandle. Low level easterly upslope flow should continue as mass response form the lee low accelerates this morning and afternoon. Deep veering wind profiles with sufficient vertical shear, in combination with the ample instability should support robust thunderstorm development from 1700-2300z. Hi-res guidance shows two primary areas of activity this afternoon. One area along the laramie range and a second area of more discrete convection along the I-80 corridor and the WY/NE border region. The latter of the two areas is the primary concern for more significant severe weather. .East Central Wyoming... The stalled front currently lying along the laramie range will serve as focus for convection early this afternoon and evening. Moisture is not as great here with dewpoints in the mid 40s expected. Regardless, SBCAPE near 500 /kg should allow scattered to numerous storms to develop around 1700z. Strong winds and large hail will be the primary threat with these storms, as most models show a linear structure developing and moving to the northeast. An isolated tornado is not out of the question along the front. However, low level shear is not as strong. SPC slight risk lines up well with current thinking. Flash Flooding is also a concern in this area with training storms and the lift from the stalled front. QPF values near 0.5 to 0.75 inches are forecast which could cause some flooding problems. The stalled front will push through as a cold front later this evening ending the severe threat as temperatures drop. .I-80 corridor and the WY/NE border... The combination of ingredients suggests a robust severe threat early this afternoon and evening. Low level shear will be maximized along the front roughly along a line from Carpenter to Bridgeport. Model soundings show bulk shear near 70 kts with low level shear in the 10 to 20 kt range. Models have not had a good handle on the low level wind fields and the low level jet this evening. Latest CYS VWP data showed very large low level hodographs with 0-1km SRH near 350 m2/s2 compared to the HRRR which showed very poor low level winds. The difference in 700 mb flow is significant, and could signal a greater tornado threat than some models currently anticipate. Regardless, most hi-res guidance shows a corridor of strong UH tracks across the southern panhandle this evening. Supercells are likely given the magnitude of vertical shear and favorable parameter space. Strong winds, large hail, and a few tornadoes look likely with these storms. Development timing is tricky, but is expected to take place across northern colorado near 1900z. Storms will exit and weaken by this evening as a cold front pushes through from the west ending the severe threat. Saturday is shaping up to be wetter and cooler as the main 500 mb wave transits overhead. Highs will be 10 to 15 degrees below average and stuck in the mid to low 50s. Further west, much colder air is expected to filter in, meaning potential for high elevation snow. Scattered showers and embedded thunderstorms are expected through the afternoon and evening hours before the trough shifts west and brings temporarily relief from the Saturday evening. Chilly overnight lows near freezing are expected for most Saturday evening. This trend is expected to continue with an active storm track through next week. .LONG TERM...(Sunday through Thursday night) Issued at 315 AM MDT Fri May 17 2019 Not many changes made to the extended portion of the forecast since all models continue to show a prolonged period of cool and unsettled weather late this weekend through late next week. Matter of fact, models are trending even more aggressive with the Pacific storm system forecast to impact the area late Sunday through Tuesday of next week. Some models are hinting to the potential of some snowfall as well across southeast Wyoming with snowlevels lowering to 5500 feet Monday night and Tuesday night. Lowering snow levels and increasing POP were the only changes made to the previous forecast to reflect current model trends. Models have trended further south with the main storm system on Monday and Tuesday, with a slow moving upper level low somewhere across east central Colorado and west central Nebraska. With ample llvl moisture and very good dynamic support at all levels of the atmosphere, there is a good potential for moderate to heavy rain with embedded thunderstorms. Will have to closely monitor the amount of cold air that enters this system on the backside, as snowfall may become more of a concern. The ECMWF and the Canadian are the coldest, showing 700mb temperatures between -4c to -6c, which is enough to support some snowfall down to about 5500 feet and accumulating snow above 6500 feet. Temperatures from Sunday night through Tuesday night will be key as current guidance suggests highs in the 40s across most of the area, which is a good 20 degrees below normal and trending colder each day. Low temperatures will likely be in the 30s with several areas below freezing across southeast Wyoming. Models show the storm system finally moving east of the area by Wednesday. However, another system will be quick to follow as another round of thunderstorms and rainfall is forecast by late Wednesday night and Thursday. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 530 PM MDT Fri May 17 2019 Wyoming TAFS...VFR at Rawlins. Wind gusts to 30 knots until 03Z, then gusts to 25 knots after 15Z Saturday. Occasional MVFR at Laramie until 01Z, otherwise VFR. Wind gusts to 30 knots after 15Z Saturday. Occasional IFR at Cheyenne until 03Z, then VFR. Wind gusts to 28 knots until 03Z, then wind gusts to 30 knots after 15Z Saturday. Nebraska TAFS...Occasional IFR at Chadron and Alliance until 03Z, then MVFR until 15Z, then VFR. Wind gusts to 25 knots after 15Z Saturday. MVFR at Scottsbluff until 03Z, then VFR until 06Z, then MVFR until 15Z, then VFR. Wind gusts to 30 knots until 03Z, then gusts to 30 knots after 15Z Saturday. Isolated thunderstorms producing IFR with gusts to 45 knots at Sidney until 03Z, then MVFR until 15Z, then VFR. Wind gusts to 30 knots after 15Z Saturday. && .FIRE WEATHER... Issued at 215 AM MDT Fri May 17 2019 Fire weather concerns are low over the next several days as a cool and wet weather pattern develop. Periods of showers and thunderstorms are possible limiting fire weather conditions && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ UPDATE...REC LONG TERM...TJT AVIATION...Rubin FIRE WEATHER...AL
Area Forecast Discussion
National Weather Service Dodge City KS
1021 PM CDT Fri May 17 2019 .UPDATE... Issued at 1021 PM CDT Fri May 17 2019 Well, clearly the cap eroded. Long track tornadic supercells have caused widespread damage across SW Kansas (refer to the latest LSRs issued by DDC). The most impressive supercell has tracked from the Oklahoma state line near Meade, and is still producing a dangerous tornado approaching Lewis. Tornado damage has occurred occasionally all along this track. Cancelled tornado watch behind the supercells. Cold front/dry line combination is now progressing through US 83 corridor, with new thunderstorms expected to develop along this boundary as it intersects moisture/instability. These are not expected to be supercellular, but still large hail/damaging wind may occur with this activity into the early morning hours. UPDATE Issued at 536 PM CDT Fri May 17 2019 Capping inversion of warm air aloft appears to be winning the battle across SW Kansas. HRRR has been one of the last holdouts calling for supercell initiation, originating from the Oklahoma panhandle. A recent attempt at initiation in Beaver county, Oklahoma on radar/satellite has failed. Pronounced dryline is clearly visible on radar, from just west of Scott City, to just west of Liberal. Its eastward momentum is ending, and will begin retreating soon. With the loss of convergence and strong capping, reduced pop grids for the next several hours. Kept a 20% mention out of respect for the extremely unstable airmass east of the dryline, but it appears convection will struggle or fail to initiate. Towards midnight, HRRR shows a rapid explosion of convection from near Dodge City to near Hays, as the cold front/dryline combination collide with the moisture/instability axis. This seems reasonable, and large hail is possible from this activity overnight. && .SHORT TERM...(This evening through Saturday) Issued at 100 PM CDT Fri May 17 2019 Depending on the strength of a capping inversion, thunderstorms will be possible this evening as short range models continue to show a strengthening field of southwesterlies aloft spreading eastward across the Western High Plains downstream of a negatively tilted upper level trough shifting across the Great Basin. As an upper level shortwave perturbation lifts northeast across the Colorado Rockies into western Nebraska, a deepening surface low in eastern Colorado will begin to lift northeast into southwest Nebraska. Meanwhile, a sharpening attendant dryline near and along the Colorado border will edge slowly eastward across west central and southwest Kansas. Ahead of the dryline, a prevailing southerly flow will draw ample moisture into the area with surface dewpoints climbing up into the lower/mid 60s(F), providing substantial instability as low/mid level lapse rates steepen. Although the strength of the cap remains an issue in regards to timing of initiation and coverage, isolated to potentially widely scattered thunderstorms will be possible early this evening in vicinity of the dryline as it advances across western Kansas. The better chance for development looks to be further north toward the I-70 corridor. Based on model soundings, favorable deep layer shear and instability with SBCAPE values in excess of 3000 J/kg suggest a significant severe potential with any storm that develops. Large hail and damaging winds will be the main threats initially with isolated tornadoes also possible. The focus for thunderstorm chances shifts east late Saturday afternoon as the main upper level trough axis moves out of the Colorado Rockies into the Western High Plains, nudging the dryline further east into central Kansas by Saturday afternoon. Meanwhile, there is fair agreement betweent the NAM/GFS/GEM/ECMWF of a secondary surface low developing generally across extreme southwest Kansas into the panhandles of Oklahoma and Texas by early afternoon with a convergence zone setting up along a developing attendant boundary extending northeast into central/north central Kansas. Dependent on recovery time from any convection the previous 12-24 hours, thunderstorms may develop in vicinity of a surface trough/dryline more toward central Kansas, then later Saturday evening in west central and portions of southwest Kansas as a cold front begins to push southeast into the area out of northeast Colorado and southwest Nebraska. As for temperatures, a drier and slightly cooler air mass will spread southeast into western Kansas tonight in wake of the advancing surface trough/dryline. Look for lows well down into the 50s(F) by early Saturday morning with a few 60s(F) still possible in south central Kansas. Expect highs only up into the 70s(F) Saturday afternoon. .LONG TERM...(Saturday night through Friday) Issued at 205 PM CDT Fri May 17 2019 Drier conditions will prevail Sunday as an upper level trough quickly lifts northeast out of the Central Plains into the Upper Midwest. Drier and cooler air will filter into the high plains behind a departing cold front limiting highs to the 70s(F) across much of the area Sunday afternoon. A few upper 60s(F) will be possible further north in west central and central Kansas. Rain chances return Monday into early Tuesday as an easterly upslope flow sets up across the Western High Plains ahead of yet another upper level low pushing eastward across the Intermountain West. With sufficient lift and moisture present, showers/thunderstorms will be possible by late Monday afternoon as a series of H5 vort maxima begin to eject out of the Desert Southwest into the high plains of western Kansas. Medium range models are in fair agreement showing stronger QFP signals, more specifically across central Kansas where the ground remains fairly saturated from heavy rainfall in the last week or so, resulting in potential flooding impacts. Easterly upslope winds will do little to erode a cooler air mass settled across the high plains to kick off the work week. Considering likely increased cloud cover and potential areas of rain, highs are expected to remain well below normal Monday before beginning to slowly recover through the middle part of the week. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 453 PM CDT Fri May 17 2019 Strong south winds gusting 35-40 kts late this afternoon will diminish rapidly this evening as the pressure gradient collapses. A capping inversion of warm air aloft is expected to prevent thunderstorm development this evening, and will remove all mention of convection from the TAFs, but will continue to monitor. Surface winds will trend light NW overnight, behind the passage of a cold front/dryline. VFR with variable amounts of cirrus will continue through tonight, with SKC by 12z Sat. Broken/overcast mid layer clouds will increase by 18z Sat as main shortwave energy arrives. Scattered showers and thunderstorms are most likely from HYS to DDC Saturday afternoon. && .PRELIMINARY POINT TEMPS/POPS... DDC 54 79 49 72 / 20 30 30 0 GCK 49 76 46 71 / 20 30 20 0 EHA 50 75 46 75 / 0 20 10 10 LBL 52 77 47 74 / 10 10 10 0 HYS 56 77 49 69 / 30 30 50 0 P28 64 79 53 74 / 30 40 50 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Turner SHORT TERM...JJohnson LONG TERM...JJohnson AVIATION...Turner
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
958 PM CDT Fri May 17 2019 .UPDATE... While CAMS models have depicted strong evening convection moving into Val Verde County, convective inhibition has won for the evening, with only the Fort Stockton supercell cluster forming in the watch area. The watch was cancelled for Val Verde County, but we are still anticipating scattered storms redeveloping over West Central TX into the southern Edwards Plateau in the predawn hours Saturday. PoP values may look a bit high for the time being, but will maintain the values as the effects of the low level jet shower should be sufficient enough with the moisture levels to generate some showers beneath the cap in the next few hours. A transition from showers to storms looks more likely to occur after 09Z. && .PREV DISCUSSION... /ISSUED 622 PM CDT Fri May 17 2019/ AVIATION... Breezy southeasterly winds will continue through much of the period as a surface low deepens well to our northeast. Think much of the overnight period will be rain free for the TAF sites outside of the possibility of a streamer shower. Will have to watch for any convection in Mexico that could move east into the vicinity of DRT. Otherwise, MVFR and perhaps IFR conditions can be expected. The CAP strength will have a big impact on what happens tomorrow. Until a clearer picture comes into view with how things will develop tonight, opted to go with VCSH with a PROB30 for TSRA in the afternoon hours for the I35 sites. Any convection should clear to the east by the evening hours with VFR expected then. PREV DISCUSSION... /ISSUED 356 PM CDT Fri May 17 2019/ SHORT TERM (Tonight through Saturday Night)... Convective development is initiating late this afternoon just to the northwest of the CWA due to boundary layer de-stabilization and orographic and dry line forcing. Isolated super cells could develop, and there is a small chance of one or two of these discrete storms reaching Val Verde county. Very steep mid level lapse rates, yielding MLCAPE values in excess of 3000 J/kg, combined with deep layer shear values of 30-40 kts will support a severe threat across western Val Verde country through the evening, with large hail the primary threat. A Severe Thunderstorm Watch has been issued through 11PM to cover Val Verde County. An upper level trough will lift out of the Rockies and into the Plains overnight and Saturday. Round two begins overnight with storms initiating to the northwest of the CWA. Many global and convective allowing models allow a complex of storms to develop across the SJT CWA. This complex could reach portions of the northern Hill Country and southern Edwards Plateau during the early morning hours on Saturday. The threat is expected to transition to more of a damaging wind threat during this time. Farther east overnight, isolated streamer showers may occur beneath the cap as 40kt low level jet develops. The convective forecast and severe potential beyond early Saturday morning is highly conditional on the cap, as is often the case with late Spring events where the main upper level support is to the north of the area. 12Z BUFR forecast soundings from the NAM12 and GFS tell the story, with the NAM12 partially eroding the cap across northern areas of the CWA while maintaining the cap the further south and east you go into the CWA. The could help explain why the NAM-3km quickly decays the squall line midday Saturday as it reaches the I-35 corridor. GFS soundings are a little more optimistic with eroding the cap farther south and east. A wide range of scenarios is depicted by 12Z CAMs, with the ARW and NSSL WRF farther south with the convective line, while the HRRR and Texas Tech WRF not showing much of anything across the CWA. Overall the PoP forecast will remain similar to the previous package, showing the highest potential for the complex of storms reaching the I-35 corridor across the northern CWA. We have included a severe potential in the grids and zones to line up with SPC Day 2 convective outlook. But again, this is all highly conditional on the cap mentioned above. A severe threat will continue through the midday and into the afternoon if the cap does erode, or forcing from the complex or line segments is able to overcome the weaker portion of the cap. Damaging winds and hail are the primary threats, although an isolated tornado threat could occur across portions of the northeast CWA. Rainfall amounts of 1/2 to 2 inches are forecast across the northern CWA and less than 1/2 inch are forecast across southern areas of the CWA, again cap conditional. There is a small threat isolated convection could linger into Saturday night as the dry line remains retreats slightly back to the west and the front never clears the area. LONG TERM (Sunday through Friday)... The next upper level trough will dig through the Great Basin and Four Corners Sunday and Monday and eject northeast into the Central Plains Tuesday. There is a slight signal in the models of precip chances across western areas of the CWA Sunday night into Monday. The tail end of the forcing comes across Monday night into Tuesday. However, once again South Central Texas will be well removed from the main forcing. Thus PoPs remain relatively low at this time. An amplified upper level pattern will develop Wednesday through Friday, with a large ridge across the Southeast U.S. and Gulf and upstream trough across the western U.S. South Central Texas will remain between the two features, resulting in breezy conditions and low level moisture trapped beneath the cap, possibly producing some isolated streamer showers. With the upper level trough far enough to the west, dry line convection should remain mainly west of the area, possible exception being Val Verde county. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 75 82 72 91 73 / 30 70 20 - - Austin Bergstrom Intl Airport 74 83 71 90 73 / 20 70 20 - - New Braunfels Muni Airport 75 82 72 91 73 / 20 60 20 - - Burnet Muni Airport 72 80 68 90 70 / 50 80 10 0 - Del Rio Intl Airport 74 92 69 95 75 / 40 30 0 0 10 Georgetown Muni Airport 74 81 71 90 72 / 30 80 20 - - Hondo Muni Airport 75 87 71 93 75 / 30 50 20 0 - San Marcos Muni Airport 74 82 71 90 73 / 20 60 20 - - La Grange - Fayette Regional 76 85 74 90 75 / 20 60 40 10 - San Antonio Intl Airport 75 83 73 92 75 / 20 50 20 - - Stinson Muni Airport 75 83 73 92 75 / 20 50 20 - - && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Aviation...Hampshire Short-Term/Long-Term...Oaks
Area Forecast Discussion
National Weather Service Fort Worth TX
713 PM CDT Fri May 17 2019 .AVIATION... /00Z TAFs/ Challenges and Concerns: Arrival of MVFR cigs/-SHRA after 06z, then timing window for strong-severe convection at all airports and when to improve conditions by 00z Sunday. Made only minor adjustments to both timing MVFR stratus northward across all airports between 04z-07z Saturday. With surface temperatures expected to remain relatively warm due to strong and occasionally gusty S/SE winds overnight and the surging stratus, cigs levels may straddle FL020 for several hours. This is due to the surface-boundary layer remaining semi-coupled. As for timing SHRA and TS, pick your poison on the CAMs with the first signs of large-scale ascent and storms occurring across the Permian Basin as of this writing. I only made slight delayed timing at DFW airports with the bulk of storms occurring between 13z-19z. Timing at Waco will be 1-2 hours delayed. I did add brief gusty westerly winds 25-40 knots in mid-late morning window of strong-severe TS TEMPO groups, along with IFR VSBY with the off and on heavier convective rainfall. Depending on whether runways at DFW are wet or not, some crosswind issues on N-S-oriented runways may occur for a few hours in the 15z-18z Saturday window at DFW International Airport. As Saturday progresses beyond 19z, it`s hard to say if new isolated-scattered TS will be able to develop with another shortwave rotating across the region. Our atmosphere will have been worked over quite well and CAMs will likely struggle to diagnose what our thermodynamic environment(instability) will actually be. I kept VCTS in through late afternoon with VFR cigs and SSW winds 20-25 knots remaining through early evening. Surface winds will back slightly and slacken to around 15 knots after 00z Sunday. 05/ && .SHORT TERM... /Issued 327 PM CDT Fri May 17 2019/ /Tonight through Saturday Night/ An active weather pattern is currently taking shape across the west with a developing upper trough centered near the Great Basin. This trough will push steadily east across the Rockies overnight/Monday, resulting in increasing large scale lift and mid level destabilization from West Texas northward to the Central Plains. North and Central Texas will remain in warm southwest flow aloft which should keep a cap in place and limit convective development through the evening. However, storms should develop over the Concho Valley during the evening as a fast moving shortwave ejects northeast from the main upper trough and interacts with a moist and unstable environment. These storms will likely become organized late this evening/overnight once a 40+ knot southeasterly low level jet develops. The high res models have been in fairly good agreement overall with regards to storm development and organization into a linear MCS overnight/Saturday morning. Given this scenario, storms would enter the western zones in the pre-dawn hours, reach the I-35 corridor by mid morning and progress eastward through the afternoon. This still is the most likely scenario, although the 18Z HRRR is now showing a much slower evolution with storms not organizing until midday Saturday. Although this solution is certainly not out of the realm of possibilities, we will maintain a model consensus forecast for now. Some strong to severe storms will be possible as the line marches eastward with damaging winds and large hail the primary hazards. Severe storms will become more likely Saturday afternoon as line moves to the east, especially if some surface heating and low level destabilization can occur. Hail and damaging wind will remain the primary threats, but there will be some tornado risk if some storms can develop out ahead of the main line (especially south of I-20 and east of I-35). Although storm chances should end from west to east through the day, there is some potential for redevelopment across the northwest zones late in the afternoon, but it will all depend on how early the line of storms comes through and how long clouds linger behind it. Therefore, we will maintain some low PoPs in all zones through the afternoon. Storms should finally end across the southeast zones Saturday night as a ridge begins to build in behind the departing upper low and a weak cold front enters the region. 79 && .LONG TERM... /Issued 327 PM CDT Fri May 17 2019/ /Sunday through Friday/ Much quieter weather is expected on Sunday with a building ridge aloft and drier air near the surface behind a weak cold front. The cold front will likely not push through the entire CWA on Sunday with the bulk of the cold air advection remaining well to the northeast. The front will likely stall near the I-20 corridor, resulting in cooler temperatures across the northern half of the region. Afternoon highs will range from the lower 80s near the Red River to the upper 80s in the south. The upper ridge will not take up residence long across the Lone Star State with another low pressure system progged to gather strength across the Great Basin Sunday night and Monday. Low level moisture will surge back to the north in response to the intensifying system with warmer, breezy and more humid air returning to the region. Thunderstorm chances will also return Monday as one lobe of energy pivots northeast towards the Central High Plains and the dryline mixes to the east. Thunderstorms will be slow to develop during the day Monday due to a cap of warm air streaming in from the Mexican Plateau. However, a few storms may develop across the northwest Monday afternoon where the cap will be most likely to break. Storm chances will increase Monday night as the lead lobe of energy lifts towards the Central Plains and the dryline moves farther east. Storms will likely organize on the dryline Monday night due to strong deep layer shear, abundant moisture and moderate instability. Severe storms will be likely given the expected variables with all modes of severe weather possible. Storms will move east across the remainder of the region Tuesday, but they should lose some of their intensity with decreasing upper dynamics and veering low level winds. Southwest flow aloft will prevail the second half of next week with a building ridge across the eastern half of the nation and a longwave trough in the west. This will keep moist southeast low level flow in place, resulting in warm weather Wednesday through Friday with highs in the mid and upper 80s and lows in the upper 60s and lower 70s. Scattered storms will be possible across the most of the region during the afternoon and evening, but the general weather pattern will keep a cap of warm air in place in the mid levels of the atmosphere. We will keep the highest PoPs in the western zones where the cap will be the weakest and the dryline will approach each afternoon.If any storms do manage to develop, they should have enough instability and shear to become strong/severe. The good news is that coverage of storms Wednesday through Friday (should they develop) will be very limited. 79 && .PRELIMINARY POINT TEMPS/POPS... Dallas-Ft. Worth 71 79 66 88 70 / 30 80 20 0 10 Waco 72 82 69 89 71 / 40 80 20 0 10 Paris 69 77 67 84 65 / 10 80 80 0 10 Denton 70 79 61 86 68 / 30 80 20 0 10 McKinney 71 78 64 85 68 / 20 80 30 0 10 Dallas 73 80 68 89 72 / 20 80 20 0 10 Terrell 71 80 68 87 69 / 20 80 50 0 10 Corsicana 72 82 70 88 71 / 20 80 50 5 10 Temple 71 82 69 89 71 / 40 80 20 0 10 Mineral Wells 68 82 58 87 67 / 60 80 0 0 10 && .FWD WATCHES/WARNINGS/ADVISORIES... None. && $$ 05
Area Forecast Discussion
National Weather Service Goodland KS
914 PM MDT Fri May 17 2019 .UPDATE... Issued at 912 PM MDT Fri May 17 2019 Just completed an update due to the expiration of the tornado watch. Had earlier made adjustments to add blowing dust and adjust other hourly grids. && .SHORT TERM...(Through Tonight) Issued at 103 PM MDT Fri May 17 2019 Overview: A lee cyclone in eastern Colorado -- associated with strengthening SW flow aloft on the eastern periphery of an upper level low progressing from NV into UT -- will track northeast into central Nebraska this afternoon and evening. Diffluent flow aloft, DPVA attendant small amplitude waves in SW flow aloft, and low-level convergence invof the aforementioned lee cyclone -- focused along a N-S oriented dryline along the CO/KS border and a WSW-ENE oriented station Scattered thunderstorms may develop during the afternoon and evening hours this weekend and early next week. Isolated severe thunderstorms will be possible.nary front extending from Washington/Yuma counties in Colorado to Dundy/Hitchcock counties in Nebraska -- will aid in the development of scattered convection across the Tri-State area this afternoon. Simulated reflectivity forecasts via the HRRR continue to indicate that isolated convection will develop along the dryline invof Goodland ~20Z and track northeast to McCook by ~23Z. HRRR simulated reflectivity forecasts suggest (albeit with less run-to-run continuity) that isolated convection may develop invof the intersection of the stationary front and dryline over central Yuma county ~21-22Z. At this time, the greatest potential for severe weather is expected along a SW-NE corridor from Sharon Springs/GoodlaScattered thunderstorms may develop during the afternoon and evening hours this weekend and early next week. Isolated severe thunderstorms will be possible.nd to Atwood/Oberlin/McCook between 20-02Z, with the most favorable environmental conditions in northeast portions of the GLD CWA where H85 dewpoints are ~16C and MLCAPE values will approach 3500 J/kg at peak heating. Steep mid-level lapse rates, strong instability, and 40-50 knots of effective deep layer shear suggest that established updrafts will quickly become robust supercells capable of producing very large hail (2-4") and damaging wind gusts up to 80 mph. Convection is initially anticipated to be high-based with relatively little tornado potential, however, tornado potential will increase with north/east extent from Goodland -- where rich low-level moisture is less likely to decrease mix-out in association with the eastward advancing dry- line -- particularly between 00-02Z as low- level shear increases in association with strengthening southerly flow /onset of the nocturnal LLJ/. .LONG TERM...(Saturday through Friday) Issued at 1240 PM MDT Fri May 17 2019 The closed low is expected to be situated over Rockies by tomorrow. As the low moves northeast, a weak ridge moves across the central Plains Sunday and Sunday night. Another trough associated with an upper level closed low begins to move back into the central U.S. Monday. As the low moves north, another low builds in behind over the west-central U.S. Tuesday. The GFS and ECMWF both have the closed low over the west-central U.S. stalling and weakening over that region as high pressure builds west from the southeastern U.S. through Friday. The GFS has the high pressure begin to weaken over the southeast U.S. Friday while the ECMWF does not show the high pressure weakening until next Saturday. A series of surface lows are expected to move across the Tri-State region throughout the extended forecast period. These lows will brings chances for rain and thunderstorms throughout much of the extended forecast period. Temperatures will warm through Thursday with a slight cooling Friday ranging from the 50s to low 80s. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 522 PM MDT Fri May 17 2019 Vfr conditions are expected through the period. For Kgld, southwest winds 22 to 27 knots with gusts of 30 to 39 knots will occur through 08z. At 08z the winds will be west at 7 knots. That will continue until 18z when they will shift to the north at 9 knots. For Kmcks, thunderstorms will quickly exit the area by 01z. South winds near 25 knots with gusts of 30 to 35 knots will shift to the west from 02z to 03z. From 06z to 07z those winds will decrease to 9 knots from the west. Those winds will continue until 22z when they shift to the north at 9 knots. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...BULLER SHORT TERM...VINCENT LONG TERM...NEWMAN AVIATION...BULLER
Area Forecast Discussion
National Weather Service Wichita KS
754 PM CDT Fri May 17 2019 ...Aviation Section Updated... .SHORT TERM...(This evening through Monday night) Issued at 317 PM CDT Fri May 17 2019 Multiple chances for strong to severe storms from tonight through tomorrow night. A strong upper trough continues to push northeast out of the four corners region. A surface low over eastern CO will continue to strengthen and slowly shift toward the NE/KS/CO region this afternoon. A dryline will sharpen through the afternoon and extend south from the low from northeast Kansas to Texas. Discrete storms are progged to develop along the dryline in western KS with perpendicular deep layer shear across the dryline. However backing occurs from 700mb to 500mb would suggest storms may be less organized. Storm development in western Kansas could glance by Central Kansas late this evening but a stronger cap in the area suggests storms may struggle to make it into the CWA. The approaching cold front with synoptic scale lift with weak CIN across Central KS could produce some strong to severe storms overnight. Likely mode is more linear overnight as deep layer flow parallels the front. Severe hail up to half dollar size with gusts up to 65 mph may be possible across Central KS and dime to quarter size hail possible across South Central and Southeast KS. Lift increases into the early morning hours from the approaching trough. This, combined with lift from the right entrance region of an upper jet and weak CIN over the area, may spark early convection across much of the area. Backing in the 700mb flow will likely hinder well organized convection in the morning, so thinking mainly strong to marginally severe storms possible. Throughout the day Saturday, enhanced lift from the trough with a stalled cold front will continue to weaken any cap across the entire area and will likely result in widespread convection. The RAP is the most aggressive with this idea. Storm mode seems the most challenging-although with such large forcing for ascent a widespread clusters seem the most plausible. Model differences exist in the strength/ position of the frontal boundary as well as the strength of the CAP. If the CAP persists more explosive convection may be possible. Main hazards that are expected with afternoon convection will be mainly severe hail up to golf ball to lime size and severe wind gusts. Messy congealing storm modes may limit even larger severe hail. However early on if a any discrete storms are able to organize all severe hazards will be possible across south central KS. Significant hail to near tennis ball size, a couple of tornadoes, and severe winds will be possible. RAP soundings indicate decent ESRH with 0- 3km CAPE near 220 j/kg and very low LCLs across south central KS. Hodographs show decent low level curvature but are rather chaotic aloft with some backing above 750mb, this does lessen the confidence in widespread sig hail/tornadoes some but the possibility does exist. Sunday is looking quiet behind the front and in a large scale subsidence pattern. .LONG TERM...(Tuesday through Friday) Issued at 317 PM CDT Fri May 17 2019 The next period of concern is Monday. Yet another upper level trough will be influencing the area Monday with a strengthening sfc low off the east. Potential for very heavy rain exists Monday into Tuesday as PW anomalies approach 3 standard deviations above normal, mainly confined to South Central and Southeast KS. Higher confidence is in the concern for flooding during this period. Large differences remain in model output of the warm front and associated instability. Further model runs will help the resolve the severe weather potential. Another shot of weather looks to hit the area mid-next week. Stay tuned for updates. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 754 PM CDT Fri May 17 2019 Primary aviation concerns: Gusty winds, LLWS, TSRA Deepening low pressure over the High Plains will allow gusty south winds to continue well into the night, along with a continued risk of LLWS as the low level jet increases. TSRA have begun developing along the dryline over western Kansas and these storms may clip portions of central KS later this evening. Given the potential, I have added a VCTS mention for that area. Storms may wane some overnight, although with the dryline/frontal boundary nearby, we cannot completely rule out SHRA/TSRA at anytime overnight. Regardless, the coverage of TSRA is expected to increase on Saturday, with a continued threat of strong to severe storms. Significant reductions in visibility are likely due to heavy rain. Which terminals will see the greatest impact is still a bit unclear, and we`ll continue to refine this area in later TAF cycles. Martin && .PRELIMINARY POINT TEMPS/POPS... Wichita-KICT 69 77 55 72 / 40 60 70 0 Hutchinson 65 76 53 71 / 40 50 70 0 Newton 68 75 53 70 / 40 60 70 10 ElDorado 69 76 54 71 / 40 70 70 10 Winfield-KWLD 70 76 55 73 / 30 70 70 0 Russell 56 77 48 69 / 40 30 60 0 Great Bend 56 77 50 70 / 30 30 60 0 Salina 65 76 52 70 / 50 60 70 10 McPherson 65 76 53 70 / 40 60 70 10 Coffeyville 70 75 57 76 / 40 80 80 10 Chanute 69 75 56 74 / 30 80 80 10 Iola 69 75 56 73 / 20 80 80 20 Parsons-KPPF 70 74 56 75 / 30 80 80 10 && .ICT WATCHES/WARNINGS/ADVISORIES... Wind Advisory until 9 PM CDT this evening for KSZ032-033-047>053- 067>069-082-083-091>093. && $$ SHORT TERM...KMB LONG TERM...KMB AVIATION...RM
National Weather Service Jackson KY
1040 PM EDT Fri May 17 2019 .UPDATE... Issued at 1040 PM EDT FRI MAY 17 2019 Did a quick update to drop PoPs and convection through the rest of the night. Also added in the latest obs/trends to the T and Td grids. These have been sent to the NDFD and web servers. UPDATE Issued at 800 PM EDT FRI MAY 17 2019 23z sfc analysis shows high pressure nudging up from the south through most of Kentucky. A wavy frontal boundary if found near the Ohio River to the north and this has proven to be the genesis for many thunderstorms late in the afternoon and early this evening with several of them severe. A couple of these cut through extreme northern parts of the JKL CWA and a severe thunderstorm watch was in effect until they passed. Luckily they all stayed below severe limits for our counties affected with mainly lightning, gusty winds, and possibly small hail the worst of the effects. So now the storms have ended for our area and the severe watch has been dropped. A stray shower or storm will still be possible in the north and east through the rest of the evening, but most will see dry and quiet weather through the night. Again some patchy river valley fog can be anticipated late tonight - especially if the sky is able to become mostly clear as expected. This has been detailed in the forecast for the rest of the night. Some rain cooled temps and lower dewpoints, post-storm, were added to the north where readings are in the lower 70s and dewpoints in the low 60s compared to upper 70s and mid 60s elsewhere. Winds have settled now approaching sunset so that light and variable conditions will ensue tonight. These updated forecast grids have been sent to the NDFD and web servers along with a freshened set of zones and HWO - sans SVR watch. && .SHORT TERM...(This evening through Saturday night) Issued at 338 PM EDT FRI MAY 17 2019 With afternoon heating are beginning to see a few showers develop across far northern KY. Have continued to carry a small chance for late afternoon and evening thunderstorms across the far north and far eastern part of the forecast area which is hinted out with some of the CAMS, including the ARW and latest HRRR runs. Do expect any showers and thunderstorms to be short lived in our area, with some support for overnight convection remaining off to our north. On Saturday upper ridging will build over the southeast U.S., and support for convection in our our area looks very limited. Appears any convection may likely be tied to terrain over the higher terrain of the Appalachians. SPC only shows a sliver of our area, right along the VA border, in the general thunder area for Saturday. Based on consistency with previous forecast will continue to carry a small chance of afternoon thunder for most of the forecast area for Saturday afternoon. Once again any shower or thunderstorm activity on Saturday will be short lived. Fairly high dewpoints in the 60s will limit ridge valley temperature differences the next two nights, but should still see minimum temperatures a little lower in the valleys, and have included this in the NDFD. With the building upper ridge we will see maximum temperatures on Saturday several degrees higher than today`s highs. .LONG TERM...(Sunday through Friday) Issued at 338 PM EDT FRI MAY 17 2019 There is good model agreement in the overall mean upper air pattern through the long term portion of the forecast, with troughing in the western U.S. and a building upper ridge over the southeast part of the country. Any ejecting short waves from the mean western trough will track to our west and north, thus keeping our chance of shower and thunderstorm activity minimal during the coming work week. Temperatures will trend to well above normal during the second half of the forecast period with the building southeast U.S. ridge dominating our weather. On Sunday a mid/upper level short wave trough and associated surface low will shift from the east central Plains into the western Great Lakes. This will result in a cold front pushing into eastern Kentucky Sunday night or Monday morning. This front will be shearing out as it approaches us, and wind fields that would support more organized convection look to stay to our west before shifting northeast. While we`ll see thunderstorm chances with this front, the severe threat is expected to remain to our west and north per the SPC Day 3 Thunderstorm Outlook. On Monday the weak front should continue to push east, working its way across the Appalachians. The shower and storm threat will continue on Monday mainly in the southeast, with the focus for significant thunderstorm activity shifting back to the southern plains with the next system emerging from the southern Rockies. This system coming out of the Rockies will again track northeast, with the heavy rain and severe weather threat once again staying to our west. The associated cold front will also once again approach our area, but will likely stall to our northwest or north, and then shift north late in the week as the southeast upper ridge builds. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) ISSUED AT 825 PM EDT FRI MAY 17 2019 VFR conditions will prevail through the forecast period at the TAF sites. An isolated thunderstorm cannot be ruled out over far northeastern and far eastern portions of the forecast area through the evening, but the chances are too low to include in the only potential TAF site - SJS - to be affected. Winds will be light and variable through the night before picking up from the southwest at 5 kts or so during the day Saturday. Again some river valley fog is expected overnight, but the TAF sites should not be affected. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GREIF SHORT TERM...SBH LONG TERM...SBH AVIATION...SBH/GREIF
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
749 PM CDT Fri May 17 2019 .SHORT TERM...(This evening through Saturday night) Issued at 250 PM CDT Fri May 17 2019 Confidence is high that rain and thunderstorms will develop later this evening and overnight along an elevated warm front that will lift northward across the region. The question remains as to where exactly this front will become active, and how far north the heaviest axis of precipitation will be. RAP13 H925 FGEN keeps the best low-level frontogenesis over northern Iowa and southern Minnesota, and usually this is a good proxy for where thunderstorms will train across the region. However, in this case there is a very strong inversion, and forecast soundings indicate that air parcels won`t become freely convective until they reach 800mb, so that would lead one to think that the thunderstorms will develop a bit farther north, as indicated by the recent runs of the HiRes models, in particular the 12Z HRRR. Was considering a flood watch with the heavy precipitation forecast overnight. PWAT values are on the order of 1.50 inches which is near record for mid-May, and usually warm fronts have the potential to over-achieve in terms of precipitation. It only takes a few thunderstorms tracking over the same area to get 2, 3, and even greater precipitation amounts. In this case, all the HiRes models are showing a pretty wide swath of precipitation. This is likely two- fold. The first is owing to the progressive nature of the northward advancing warm front, but perhaps the second more important reason is the steering winds, that is the winds north of the on top of the inversion, are nearly unidirectional from the southwest, so that should push the storms to the north quite quickly. This can be seen in the elevated storms that formed in northeast Nebraska early this afternoon. For these reasons, we might not have the potential for the higher-end rainfall amounts, so did not go forward with a flood watch at this time. Confidence is lower in the forecast for Saturday. Once the storms move out Saturday morning, we`ll have overcast skies. The surface low is forecast to track eastward along I-90, and instability will build ahead of it so by the late afternoon we could see MUCAPE values of 2000 to 2500 J/kg. If this scenario ends up, we could have a legitimate threat for severe storms in the afternoon and evening. The elevated mixed layer with this setup is quite impressive, on the order of 8C/km, and this type of setup leads to fat CAPE soundings, which results in strong updrafts and severe hail. SPC has lifted the slight risk of severe weather to account for this. There is still a slight inversion, so might not have the surface-based potential for tornadoes, but this could change across southeast Minnesota if we end up heating the boundary layer above what the models are forecasting. Continued the previous shift`s trend of warming highs along I-90. Meanwhile the rest of the forecast area will be cool, windy, and cloudy with occasional showers and drizzle. .LONG TERM...(Sunday through Friday) Issued at 255 PM CDT Fri May 17 2019 In the wake of the heavier rainfall through Saturday night, Sunday will see periods of showers, especially in the morning, but the intensity will be lighter. Models are now nearly consistent on the evolution of the upper features, and the same on the surface low by Sunday morning. This area of low pressure will be near southeast Minnesota with heavier bands of rain along, and north of the track of this surface low across west central Wisconsin Sunday morning. Farther to the west, and southwest, the rainfall will gradually decrease to scattered showers by the afternoon, before ending. It will be very cool for the middle of May with highs only reaching the mid to upper 40s. There could even be some record low maximums on Sunday if highs only reach the mid 40s. The current records for Sunday are 43 degrees (1971) in Minneapolis/St. Paul, 43 degrees (1971) in St. Cloud, and 49 degrees (1963) in Eau Claire, Wisconsin respectfully. In addition to the temperatures, a raw north/northeast wind gusting up to 30 to 40 mph, will accompany this cool temperatures. Once this system departs Sunday night, there is a potential of frost in central Minnesota where temperatures fall into the 30s. This is dependent on the amount of wind, and cloud cover, but something to keep in mind Monday morning. As with previous discussions, the upper level pattern will remain very active for the Upper Midwest through next week. There could be a window of 36-48 hours (dry weather) before the next system ejects out of the Rockies and into the Plains Tuesday night/Wednesday. There still remains uncertainties for next week system as to whether it will be cool (GFS), or warmer (EC/GEM), as the system ejects out of the Rockies and into the Upper Midwest/Northern Plains. The differences in the models are related to the strength of the ridge building across the southeastern CONUS. The 5-day 500MB average mean heights continue to support a very strong ridge forming in the southeast CONUS. If models continue to support this stronger scenario, the system ejecting out of the Rockies will likely move farther to the west, and allow for warmer air over our region. It doesn`t mean we won`t get precipitation, it means that instead of cool and showery, it will be humid and unstable. Due to the anomalous type of pattern, and the strength of the system, I wouldn`t be surprised to see severe weather in the Upper Midwest sometime the middle of next week. The is still another storm system moving out of the Rockies late next week. Due to the strong ridge over the southeastern CONUS, this system will likely be farther to the west than the current models indicate. Overall, Sunday will be cool, wet and windy. Monday and early Tuesday will be dry, and a good chance of precipitation redevelops by Tuesday night, and into Wednesday. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 749 PM CDT Fri May 17 2019 Dry east winds have kept rain and MVFR cigs at bay today, but as the storm system to our west has begun lifting north across Nebraska, we`re finally starting to see lower level moisture expand north, as seen in the rapid expansion of cigs in the 4-6k foot range. Generally agree with what the HRRR shows in that an E-W band of showers with embedded Tstorms develops around 3z near the MN river and lifts northeast, with a N-S line of thunderstorms coming out of SoDak and moving across the area late tonight. Behind this line of storms, forecast soundings show the mid/upper levels really drying out, with copious amounts of moisture trapped beneath a strong inversion. This will result in IFR or lower stratus much of the day, but likely very little in the way of precip outside of drizzle. For MKT, will have to watch how far north the warm front makes it in MN. Right now, have MKT remaining north of the warm front, but they could sneak on the other side briefly in the afternoon, which would result in VFR conditions and southerly winds there for a time. KMSP...Showers with occasional TSRA expected to start around 5z, with a line of storms arriving around 11z. By 14z, precip chances look minimal outside of drizzle, with a more concentrated area of rain not arriving until closer to 00z. /OUTLOOK FOR KMSP/ Sun...IFR/MVFR. -SHRA. Wind NE 20G30 kts. Mon...VFR. Wind NE 5 kts. Tue...VFR. MVFR and IFR/-SHRA likely late. Wind E at 15G25 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. && $$ SHORT TERM...JRB LONG TERM...JLT AVIATION...MPG
Area Forecast Discussion
National Weather Service New York NY
1021 PM EDT Fri May 17 2019 .SYNOPSIS... A cold front will moves east of the area during tonight, followed by building high pressure into Saturday. The high moves offshore Saturday afternoon through Saturday night. High pres remains over the Atlantic on Sun, with a cold frontal passage late Mon night into Tuesday. A weak frontal system may impact the area during the middle of the weak. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... A cluster of showers moves from WNW to ESE to along a cold front which slides across far eastern portions of the CWA towards, and just after midnight. Therefore by 4-5z the entire region should by dry. Upped temps slightly from previous due to drier air lagging behind the front slightly as the RAP analysis shows. Therefore the much lower humidity / dewpoint readings come in closer to daybreak. Before then the drier air will move in gradually. We should get enough of a NW flow right behind the front to preclude fog, but cannot rule out some patchy fog where a few showers occurred where the ground is damp. In any event, skies will clear nicely for the overnight and into Saturday morning. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... Deep layered ridging builds across the area Saturday as surface high pressure builds into the region. The ridge begins to weaken toward 21Z Saturday and through Saturday night as the next longwave trough digs into the central plains. A warm front will be strengthening Saturday night, with the best lift well to the west and north by late Saturday night. Ridging should hold off the progression of the front Saturday night and will leave Saturday night dry at this time. && .LONG TERM /SUNDAY THROUGH FRIDAY/... Sly onshore flow keeps much of the cwa cooler than upr temp potential on Sun. Areas w of the Hudson however should approach 80 or abv. The limiting factor there will be a sea breeze that will likely arc nwwd thru the day. The models hint at some weak pockets of energy rotating thru the flow. While these could produce a stray shwr, the prob and coverage is too low to include in the fcst attm. Heights fall Sun ngt thru Mon ahead of a cold front. The fropa looks to be 6-12z Tue attm. Until then, sct shwrs and tstms are expected. Timing will dictate any severe threat, but activity Sun ngt lingering into Mon could limit instability and work over the atmosphere too much ahead of the approaching h5 trof. If activity holds off til Mon aftn, some severe is more likely. Some fog is also possible till the fropa, with the possibility of a fog bank developing over the ocean which could have a huge impact on s shore LI weather and temps should it form and hug the coast. Tue is a dry fcst with hipres quickly drifting thru. Thereafter, the ECMWF remains a much drier soln, with the high suppressing rainfall chances til Thu ngt with a strong shrtwv rounding the ridge. The GFS is more active, with waa shwrs and perhaps tstms ahead of this next feature. Pops were limited to 40 percent as a result. The NBM was used for temps, although highs were raised slightly abv for Sun. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... Cold front will pass through the terminals the next few hours with perhaps a passing shower. Winds shift to the NW at 5-10 kt behind the front. There could be a few gusts 15-20kt right behind the cold front. There is also some uncertainty Saturday afternoon with the timing of the wind shift to the S-SW and local seabreezes. This could vary by several hours. .OUTLOOK FOR 00Z SUNDAY THROUGH WEDNESDAY... .Saturday night-Sunday...VFR. .Sunday night through Monday....MVFR conds possible at times, with chance of showers/tstms. .Tuesday...VFR. .Wednesday...MVFR conds possible at times, with chance of showers and possibly a tstm. && .MARINE... The southerly flow ahead of an approaching cold front has not been as strong as expected with both winds and gusts remaining below 25 kt. There may be occasional gusts approaching 20-25 kt early this evening as storms and the cold front move into the forecast waters. Also, ocean seas remained below 5 feet. Winds and seas will remain below SCA levels tonight through Saturday night as high pressure builds into the waters, and then moves east Saturday night. Winds and seas are expected to stay blw sca lvls Sun, then sca conditions are possible Mon into Tue, especially on the ocean. Winds and seas are likely to fall blw sca lvls Wed and Thu. && .HYDROLOGY... Significant rainfall is not expected through midweek. No widespread hydrologic impacts are expected through next Friday. && .TIDES/COASTAL FLOODING... Tides will be running astronomically high the next couple of days due to a full moon on the 18th. Minor coastal flooding will be a possibility for southwest CT shorelines. A Coastal Flood Statement is in effect for Southern Westchester and Southern Fairfield shorelines 10PM-1AM tonight. Another minor coastal flooding event is possible for Saturday evening during high tide as well for the same area with the continuation of southerly flow. && .EQUIPMENT... NYC NOAA Weather Radio Station KWO35 (162.55 MHz) remains off the air. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JMC/19 NEAR TERM...JE SHORT TERM...19 LONG TERM...JMC AVIATION...DW MARINE...JMC/19 HYDROLOGY...JMC/19 TIDES/COASTAL FLOODING...// EQUIPMENT...//
Area Forecast Discussion
National Weather Service Shreveport LA
933 PM CDT Fri May 17 2019 .UPDATE... IR Satellite Imagery this evening showing building low level cumulus across SE TX and that moisture will be spreading and expanding north and eastward overnight into Saturday Morning. Taking a look at regional radar mosaics, convection across the TX Hill Country which was supposed to be expanding and growing in coverage is instead, confined to a lone supercell thunderstorm southwest of San Angelo, Tx. The new 00z NAM output has a good handle on this attm, but does indicate convection beginning to develop after midnight somewhere in the San Angelo/Midland area and vicinity with this convection growing in coverage and intensity as it moves northeastward into NC TX and much of Central and Northeast OK by 18z on Saturday. This is quite a bit different than the latest HRRR and HREF output which suggests that a strengthening MCS to our west would begin moving into our far northwest zones as early as Noon on Saturday. The earlier arrival of storms across our area on Saturday would play a big role in us not destabilizing as much as if the storms were to begin entering our northwest zones later in the afternoon or early evening as a host of other model suites suggest. For the update this evening, did remove slight chance pop mention after midnight across our extreme west as just don`t see anything approaching our far western counties through sunrise in the morning, even if we see increased coverage across far West Texas later tonight. Temperatures are in the ballpark so made no changes in this department. Given the uncertainty in timing of the convection addressed above, chose not to issue a Lake Wind Advisory with this update but a later arrival of storms would allow for even more mixing down of stronger winds in the lower levels with Lake Wind Advisory likely being met, at least across our western half for Sat. Update out shortly...13. && .PREV DISCUSSION... /issued 449 PM CDT Fri May 17 2019/ AVIATION... Scattered cu field across our airspace this afternoon affecting all terminal locations with the exception of the ELD and MLU terminals. This is the leading edge of low level moisture return that will turn into MVFR ceilings late tonight. A tight pressure gradient will result in SSE winds overnight ranging from near 5kts across NE LA to near 12kts at the TYR terminal. With sufficient mixing in the 14z-16z timeframe on Saturday, look for these winds to increase with sustained SSE winds near 12-18kts with gusts upwards of 30kts across our NE TX terminal locations. Look for MVFR ceilings by late morning into the afternoon on Saturday to either scatter out across our eastern terminals or lift to near 35hdft to 45hdft across our western terminals. Did introduce VCTS at the TYR/TXK terminals with this 00z TAF package at 18/21z with additional mentions further east and later in time with our remaining terminal locations. This will be addressed with the 06z TAF package later tonight. 13 && .PRELIMINARY POINT TEMPS/POPS... SHV 68 85 70 87 / 0 40 60 20 MLU 67 86 72 86 / 0 40 70 60 DEQ 67 82 67 85 / 10 60 70 20 TXK 67 83 69 86 / 10 50 70 20 ELD 65 86 70 86 / 0 40 70 30 TYR 69 84 70 86 / 10 70 70 10 GGG 69 85 70 87 / 10 50 70 20 LFK 69 87 70 87 / 10 50 50 30 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...None. TX...None. && $$ 13/13
Area Forecast Discussion
National Weather Service San Angelo TX
610 PM CDT Fri May 17 2019 .AVIATION... /00Z TAFS/ VFR conditions and gusty south and southeast winds will continue across West Central Texas terminals into the early morning hours. However, most models suggest a squall line of storms to develop and sweep across the area overnight and into sunrise Saturday morning. Once the timing becomes a little more certain, amendments will be made to pin down the timing. Otherwise, MVFR cigs may briefly reach the southern terminals before the convection arrives, with all areas seeing improving conditions once the storms exit to the east. && .PREV DISCUSSION... /issued 321 PM CDT Fri May 17 2019/ SHORT TERM... (Tonight and Saturday) ..Strong to severe storms expected tonight... Early this afternoon, a dryline was situated west of the area and extended from near Lubbock, southwest to near Midland and then just west of a Ft Stockton. Visible satellite imagery as of 2 PM shows some enhanced cumulus developing just east of the dryline over Pecos county. Hi resolution models continue to show some isolated storms developing over this region between 3 PM and 6 PM, due to strong surface heating and a weakening CAP along the dryline. Most of the hi-res models weaken the storms through early evening as they encounter a stronger capping inversion to the east. The latest HRRR is the most bullish and brings storms into western portions of the Northern Edwards Plateau and western Concho Valley through 8 PM, before weakening. If storms develop, they will likely become severe, given MLCAPES around 3500 J/Kg and deep layer shear between 30 and 40 Kt. The main hazards should storms develop, would be large hail in excess of 2 inches and possibly an isolated tornado. Thunderstorms are expected to increase along the dryline to our west by mid to late evening as lift increases with the approach of an upper level trough and wind fields strengthen aloft. Models generally agree that storms will increase in coverage across western portions of the forecast area around midnight, then move east as a line or broken line of storms through the overnight hours into early Saturday morning. Storms may initially be discrete across western sections, with large hail (in excess of 2 inches) possible, along with isolated tornadoes. The severe threat will gradually transition into a damaging wind hazard across eastern sections by early Saturday morning. In addition, very heavy rainfall will accompany some of the storms, which may result in localized flash flooding given the already moist soils from recent rains. Thunderstorms are expected to end across eastern sections by late morning or early afternoon as a Pacific front moves through, bringing drier air and gusty southwest to west winds by afternoon. LONG TERM... (Saturday night through Sunday) The upper level low responsible for our severe weather Friday night/Saturday morning will lift off into the Great Lakes region by Sunday morning. Warm and dry conditions will prevail during the afternoon, with highs in the upper 80s to lower 90s. The next upper level low pressure system will set up across the Great Basin by Monday. Meanwhile, the dry line will sharpen near or along our western CWA border during the afternoon. Showers and thunderstorms are forecast to develop along the dry line by Monday afternoon and then spread eastward across our area Monday evening and into Tuesday morning. Instability/shear parameters still look favorable for another bout of severe weather, and we will continue to monitor this portion of the forecast closely. Otherwise, expect highs on Monday in the mid 80s under mostly cloudy skies. Dry line/Pacific front sweeps across the region Tuesday afternoon brining rain chances to an end. Expect highs again in the 80s. Wednesday and beyond, our area will be positioned between an upper level ridge over the southeastern U.S. and a broad upper trough over the western U.S. This will maintain southwesterly flow aloft across west Texas. Showers and thunderstorms will be possible each afternoon depending on the position of the dry line and subtle disturbances aloft in the southwesterly flow. Thus, will keep a slight chance of PoPs going in the extended forecast. && .PRELIMINARY POINT TEMPS/POPS... Abilene 66 83 57 88 / 80 60 0 0 San Angelo 67 85 56 90 / 80 40 0 0 Junction 71 85 60 92 / 70 70 0 0 Brownwood 69 82 56 88 / 80 80 0 0 Sweetwater 65 83 57 87 / 70 30 0 0 Ozona 67 85 56 89 / 80 30 0 0 && .SJT WATCHES/WARNINGS/ADVISORIES... None. && $$ 07/99/99
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