Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/25/19


AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
920 PM EDT Mon Jun 24 2019 .SYNOPSIS... A trough of low pressure will cross the region tonight, then linger along the coast Tuesday. High pressure builds into the area from Tuesday night through Friday. && .NEAR TERM /UNTIL 8 AM TUESDAY MORNING/... As of 845 PM EDT Monday... Latest analysis indicating a sfc trough of low pressure over the region with an upper level ridge axis along the coast and progged to move offshore overnight. Meanwhile, an upper trough is situated across the western Great Lakes region, and is progged by the models to weaken overnight while moving ENE. Earlier tstm activity over the northern zones has generally diminished, but there is a lot of ongoing convection upstream over western VA/western NC/SC. Little in the way of precipitation is expected through the next few hrs, then following fairly close to the past few runs of the HRRR and HREF means yields showers and tstms advancing E into the Piedmont close to midnight and shifting E/NE with time before diminishing between 06-09Z. Have raised PoPs to likely (~60%) for a few hrs over the northern Piedmont counties, with high chance (40-50%) for scattered showers/tstms into metro RIC and most of the I-95 corridor, tapered to just a slight chance over most of SE VA and NE NC where heights aloft look to keep conditions a little more capped and stable (though not completely so). This overnight activity is not expected to be severe, but some locally heavy rain will likely accompany some of the storms given Precipitable Water values from 1.70" to nearly 2.00". There is just enough shear and remaining instability that a few storms could contain some strong gusty winds to around 40 mph. Currently very warm and humid across the area with areas that did not receive any rain from earlier this evening still mostly in the upper 70s to lower 80s with dew pts in the low to mid 70s. Overnight lows will be primarily from 70 to 75F, with a few upper 60s in the Piedmont. && .SHORT TERM /8 AM TUESDAY MORNING THROUGH THURSDAY/... As of 330 PM EDT Monday... Models show the boundary lingering along the coast Tue with high pressure building east across the mts. A weak impulse may add an additional trigger for aftn convection along the sern coastal areas (inducing local seabreezes). Thus will keep slight chance/low chc PoPs mainly from the Ches Bay east towards the coast. Otw, pt to mostly sunny. Highs upr 80s-lwr 90s, cooler at the beaches. High pressure builds into the region Tues night, moves across the area Wed, the settles off the coast Wed night/Thu. Dry through this period, although there may be a lingering convection across the coastal waters Tue eve. Lows Tue night mid 60s-lwr 70s. Highs both Wed/Thu upr 80s-lwr 90s, cooler at the beaches. Lows Wed night upr 60s-lwr 70s. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... As of 330 PM EDT Monday... Very warm-hot/mainly dry wx expected through Fri as an upper ridge remains near the SE CONUS coast. At the surface, high pressure remains anchored just off the Carolina coast from Thu-Fri. Cannot rule out isolated late aftn/evening tstms across the Piedmont on Fri, but kept PoPs aob 14%. Blend of the models continues to suggest that an upper low/trough aloft drops SSE from Ontario/Quebec to the Northeast CONUS coast late Sat-Mon. This may result in better tstm chances on Sat/Sun (highest during the late aftn-evening) before a cold front crosses the region Sun night. Still does not look like a lot of tstm coverage on this weekend (even w/ the cold FROPA late Sun-Sun night), so have kept PoPs in the 15-30% range. Highs Fri-Sun mainly in the 90-95F range...with morning lows mainly in the low 70s (w/ mid 70s across portions of coastal SE VA/NE NC). Slightly cooler behind the front on Mon, with highs in the mid-upper 80s (and morning lows mainly in the upper 60s) && .AVIATION /01Z TUESDAY THROUGH SATURDAY/... As of 755 PM EDT Monday... VFR conditions are expected thru most of the forecast period. While there are a few SHRAs invof SBY right now, a broken line of SHRAs/tstms has developed from WV southward to the mountains of VA/NC. This line of SHRAs/tstms (associated w/ a trough of low pressure) will move toward the terminals during the next few hours, but is expected to weaken as it does so. RIC stands the best chc of seeing a tstm, while mainly SHRAs are possible at SBY. The chc of pcpn is low (~20%) across the southeastern terminals, so have left any mention of pcpn out of the TAFs. CIGS remain VFR even as the aforementioned line of SHRAs/tstms moves through (in a weakened state). Brief IFR VSBYs are likely in the heavier SHRAs/tstms. Have a TEMPO group for SHRAs at RIC from 02-05z, but only mentioned VCSH at SBY for now. Pcpn chances end from W to E later tonight as the trough of low pressure crosses the area. Southerly winds turn to the NW by Tue AM at all sites, but remain around 10 kt. Local sea breezes will dominate Tue PM with respect to wind. There is a slight chc of aftn SHRAs near the coast Tue PM. Otherwise, dry on Tue w/ SCT CU (4-6k ft) during the aftn. OUTLOOK...Expect mainly VFR (dry) conditions Tue night thru Fri. && .MARINE... As of 330 PM EDT Monday... Afternoon surface analysis shows high pressure off the Southeast coast leading to southerly flow across the region. Winds have increased to 10-15 knots and backed a bit to southeasterly as a surface trough approaches from the west. Waves and seas are generally around 2 ft but will increase to 2-3 ft this evening under continued SSE flow. While a few gusts nearing SCA levels will be possible this evening into the overnight, opted not to issue any headlines with sustained winds topping out around 15 knots. There is a chance for a few showers and storms later this evening but trends in hi-res models today have been toward lesser coverage and intensity across the marine zones tonight. A weak, convectively-enhanced, trough will cross the area on Tuesday with winds veering around to the west and northwest in the Bay for a period before southerly flow briefly resumes ahead of a weak cold front. The front crosses the area late Tuesday/early Wednesday, but with little to no airmass change behind the front, winds will become NNE but remain aob 10 knots in its wake, becoming SSE by Wed night. The remainder of the week will see generally quiet marine conditions with prevailing southerly flow, ~10-15 knots, and waves/seas 1-2 ft. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...None. && $$ SYNOPSIS...LKB NEAR TERM...LKB/MPR SHORT TERM...MPR LONG TERM...ERI AVIATION...ERI/MPR MARINE...RHR
Area Forecast Discussion
National Weather Service La Crosse WI
645 PM CDT Mon Jun 24 2019 .SHORT TERM...(Tonight into Wednesday) Issued at 215 PM CDT Mon Jun 24 2019 Cold front has swept east of the local area, but scattered convective firing just behind it, in a ribbon of instability and increasing low/mid level lapse rates. RAP suggests 1500 J/kg in SBCAPE although wind shear is weak at best. That said, could be enough for a few stronger storms. Threat leans toward hail, but with drying in the low levels post the front, inverted-v sounding would support enhanced downdrafts. This strong storm potential should exit east between 21-23z (isolated severe can`t be ruled out) but a few more showers/storms will be found behind that, associated with an upper level piece of energy slipping in from the northwest. These will linger into late evening before diminishing/ending. On Tue, another bit of upper level energy will drive eastward across the region, pushing another sfc front ahead of it. Drier air mass to work on and most models aren`t very enthusiastic with rain potential (smattering of chances). That said, could see upwards of 1500-2000 J/kg of SBCAPE develop across northeast IA/southwest WI for the afternoon. The NAM and GFS are more aggressive with CAPE, but also more robust with dewpoints - overly so. Low 60s more reasonable in those areas. That said, rather dry sub cloud layer per bufkit soundings would promote mixing, drying out the dewpoints across the area and carving away the instability. Shear is decent and would support storm development, but mostly in the 0-3 km layer (+30 kts). Low level moisture transport mostly progged to feed the southern extended of the front, across southern/eastern IA. So, some potential for a few stronger (severe?) storms if storms can fire - and that is the bigger question. Convergence is weak along the norhtern front as it moves through, better across southern IA. Shortwave energy is there, but farther north, even more removed from the more favorable atmosphere. Front could/will probably be enough to fire up a few storms, but think the higher threat/better chances will be across southern IA...maybe eastern WI. Wednesday looks similar to Tue although perhaps without the small rain chances. Various weak perturbations in the quick moving upper level flow, but not much saturation to work on, nor much agreement between/within the models. .LONG TERM...(Thursday through Monday) Issued at 215 PM CDT Mon Jun 24 2019 It`s all about the heat and humidity for the end of the week. Models remain in favor of upper level ridge amplification across the plains as the week wears on. The hottest air (mid 20s C 850mb temps) looks to hold across the plains - but NAEFS anomalies point to around +1 for 850mb temps locally. Highs in the mid 80s to around 90 should result. Steady southerly fetch also means a tap into gulf moisture. Sfc dewpoints in the mid 60s to around 70 look reasonable. So for those hankering for some summer heat and humidity - here it is. Don`t think we will move into heat advisory criteria, but it`s definitely going to be a period of very warm/humid conditions and the appropriate precautions should be taken (moreso having not dealt with this kind of airmass this summer yet). While the region is coming under the influence of the upper level ridge to the west, the GFS and EC suggest ripples in the flow will ride across the ridge bringing sporadic shower/storm chances. In addition, mcs activity over the northern plains could track mcvs through the Upper Mississippi River Valley - another potential focus for shower/storm development. Trying to pinpoint timing/location of any of these features is an exercise in futility this far out...so will let the model blend dictate rain chances for now. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 642 PM CDT Mon Jun 24 2019 VFR expected at the TAF sites. Will monitor for a late night chance /KRST and KLSE/ and Tuesday afternoon /KLSE only/ chance for a TSRA as weather impulses move out of the Dakotas overnight. Confidence and probabilities are too low to include into the TAF at this time. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ SHORT TERM...Rieck LONG TERM....Rieck AVIATION...Kurz
Area Forecast Discussion
National Weather Service State College PA
1054 PM EDT Mon Jun 24 2019 .SYNOPSIS... A cold front will push through central Pennsylvania tonight and early Tuesday. Building heights are expected across the Mid Atlantic region during the second half of the week. A cold front will likely push south across the region by early next weekend. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... The lines entering central PA continue to weaken as they are entering a cooler, more stable air mass. The ridge, though weakening as it moves east, continues to stifle the approaching convection. The setting sun has deprived the showers and storms of its heating so expect these storms to continue to weaken as it moves through PA. Still don`t rule out isolated thunder embedded in the line overnight. The strongest convection is currently south of the Mason Dixon and making its way into Somerset county. expect these storms to move NW into the region overnight. Have adjusted timing to the latest HRRR and the radar. However the timing is very consistent to previous thinking, and have only tweaked to get slightly finer timing using the HRRR and RAP as basis. The cold front is back in Ohio and will moving through the region overnight into Tuesday morning. not expecting any flooding as the storms are not training over the same region and are moving fairly fast. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/... Showers should be exiting the eastern part of the forecast area early Tuesday, as cold front pushes east. Surface ridging building into the state should translate to fair weather for the rest of the day over most of central Pa. However, cooling temps aloft, combined with diurnal heating, could result in a few afternoon sprinkles across the NW mountains. With the upper trough lifting out, the post cold frontal airmass will be drier but not significantly cooler. Highs will range from the mid 70s NW to mid 80s SE, which will be a few deg either side of normal. && .LONG TERM /TUESDAY NIGHT THROUGH MONDAY/... A summertime pattern will arrive right on schedule with above average temperatures and humid/muggy conditions to close out the month of June. A theme of drier weather is also expected through most of the week with just an isolated shower or thunderstorm possible. A digging upper trough over the Northeast US will bring the most likely period of t-storms to the area over the weekend. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... Line of showers and storms is currently moving into eastern PA. These storms have reached the east central TAF sites of BFD JST and AOO. Have removed VCTS from most TAFS, the thunder along the lines are becoming more isolated but given that some exists have gone with VCTS for BFD and JST. These storms will weaken as they move eastward. Latest HRRR continues to bring them through central PA through the first half of the overnight period. Showers could linger though the NW into early tomorrow morning. MVFR cigs and vsbys are possible mainly after 09Z. BFD could see showers linger until around 10Z. MVFR cigs, with periods of IFR cigs possible at BFD and IPT, will improve slowly until around 15Z. As the SFC mixes out expect gusty west winds upwards of 25kts. .Outlook... Wed...Scattered PM thunderstorms possible NW. Thu...No sig wx. Fri...Scattered PM thunderstorms possible NW. Sat...Chance of mainly PM showers and T-storms. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...La Corte NEAR TERM...Dangelo/Ceru SHORT TERM...Fitzgerald LONG TERM...Steinbugl AVIATION...La Corte/Ceru
Area Forecast Discussion
National Weather Service Fort Worth TX
642 PM CDT Mon Jun 24 2019 .AVIATION... /00z TAFs/ Challenges: With the airmass over the region still recovering from MCS-washout(stabilization) the past 24 hours and weak 925mb flow expected, timing MVFR cigs into all airports by daybreak Tuesday is a bit problematic. Low confidence TS chances beyond 21z Tuesday also a concern. Right now, an expansive cirrostratus canopy remains overhead, particularly over Waco and Central Texas. Scattered severe TS have developed well to the west on the old MCS outflow, but are not expected to impact terminals and should remain well west tonight. 925mb flow is expected to recover overnight from the S at 20-25 knots. RAP/NAM model guidance/soundings are struggling a bit on timing of MVFR cigs on this modest 925mb flow, but have maintained a time either side of 12z for arrival into airports. Waco 10z-11z, DFW airports likely 12z-13z. There are signs on RAP soundings that at least scattered clouds BLO FL010 or some MVFR/BR may be possible with light ESE winds. At this time, with 925mb flow on the weak side and uncertainty on the cirrostratus canopy, I will only introduce scattered clouds in the IFR layer and just maintain prevailing MVFR cigs BLO FL015. All airports will see MVFR cigs throughout the post daybreak hours, with low level warming allowing a slow rise into low MVFR by 17z-18z Tuesday. TTU WRF does show some low TS potential in the 22z Tues-01z Wed period and scattering of cigs, but confidence was too low at this time to introduce into the forecast. Otherwise, light E/SE winds less than 10 knots, will veer southerly 10-12 knots by Tuesday afternoon. 05/ && .SHORT TERM... /Issued 314 PM CDT Mon Jun 24 2019/ /Tonight/ Abundant cloud cover and cool thunderstorm outflows are keeping below normal temperatures across the region this afternoon. The cloud cover will linger through the night and dewpoints will remain in the upper 60s and lower 70s. Therefore, overnight lows should be on the warm side with lower and middle 70s in most locations. The only other concern tonight will be the potential for thunderstorms. The atmosphere will remain moderately unstable tonight and a shortwave is progged to move east out of West Texas. Storms will likely develop west and southwest of the region this evening and weaken as they move east into a more capped environment across North Texas. Therefore, we will only keep slight chance PoPs through the night. 79 && .LONG TERM... /Issued 314 PM CDT Mon Jun 24 2019/ /Tuesday through Monday/ The weather pattern will change over the next week as we shift from upper level westerlies to easterlies in response to a subtropical high building over northern Mexico and moving into the Central Plains. Before this occurs we`ll have one more weak shortwave slowly trough track through the region Tuesday, which when combined with a moist and unstable airmass, should spark off scattered showers and storms. Most of the activity will be in the afternoon and early evening hours and to the east of the I-35 corridor where PoPs will be near 50%. These PoPs will taper off to 20% in the western zones. Low temperatures will be in the low to mid 70s and highs will be held down by the increased cloud cover ranging from mid 80s in the east to near 90 elsewhere. On Wednesday very weak northerly upper level flow will become established over the region and this could allow an MCS that develops in Kansas Tuesday night to drop south into northeast Texas during the day. Since the model guidance is split on whether this will even survive the trip through Oklahoma will keep PoPs at just 20-30% over the northeastern zones. Otherwise with the increased sunshine, temperatures will warm a couple degrees, but still near normal for late June. By Thursday and Friday upper level ridging looks to be close enough for subsidence to dominate and keep the region dry. High temperatures will tick upwards into the low to possibly mid 90s. Lows will remain near normal in the mid 70s as light winds and clear skies will prevail at night. By the weekend the upper level high will have moved into the Plains and an inverted weakness aloft will develop over the region. This combined with adequate moisture over the eastern zones likely will lead to some generic isolated afternoon showers and storms. High temperatures may cool a degree or two as the low level fetch becomes southerly off of the "cooler" Gulf of Mexico. TR.92 && .PRELIMINARY POINT TEMPS/POPS... Dallas-Ft. Worth 74 90 72 91 73 / 20 30 20 10 10 Waco 74 89 72 92 71 / 20 30 30 10 5 Paris 71 86 68 86 70 / 20 40 20 30 10 Denton 72 89 71 91 72 / 20 30 20 10 10 McKinney 73 88 71 89 72 / 20 30 20 20 10 Dallas 74 90 72 91 73 / 20 30 20 10 10 Terrell 73 88 71 89 72 / 20 40 30 10 10 Corsicana 71 87 70 88 70 / 20 40 30 10 10 Temple 74 90 72 91 71 / 20 30 30 10 5 Mineral Wells 70 89 69 90 69 / 20 20 20 10 5 && .FWD WATCHES/WARNINGS/ADVISORIES... None. && $$ 05/08
Area Forecast Discussion
National Weather Service Wilmington NC
1028 PM EDT Mon Jun 24 2019 .SYNOPSIS... A front will approach the Carolinas from the west weakening as it moves toward the coast tonight. High pressure will build slowly into the Carolinas behind it leading to hot and drier weather through mid-week. Shower and thunderstorm coverage will increase Friday through the weekend as high pressure shifts off shore. && .NEAR TERM /THROUGH TUESDAY NIGHT/... As of 10 PM Monday...Tstorm activity approaching from the west continues to weaken. Models indifferent in handling this activity but given real time tendencies, will continue the weakening trend with activity likely isolated in coverage by the time it pushes east into our western portions of the ILM CWA. Pcpn will generally be under 0.05 inches. Have updated sky conditions by increasing low and mid-level clouds with majority of these being convective debris clouds. Eventually high level debris ci/cs will dominate bkn/ovc into daylight Tue. Have tweaked temps a degree or 2 but no categorical changes. Previous................................................. As of 3 PM Monday...Mid level ridge moves off the coast tonight allowing for shortwave trough to approach from the west. Agreement is poor between various models as to whether or not the associated precip makes it into the area. The wet outlier solution of the GFS appears to be suffering from convective feedback upstream and seems to have energy too far south. The WRF has no precipitation whatsoever. The HRRR has a line that moves into mainly inland SC counties before dissipates. This solution not only appears the most plausible but also seems to match well with previous thinking. The trough axis doensn`t move offshore until about 18Z Tuesday but with the diurnal lack of instability beforehand the morning will be dry. The afternoon will then remain rain-free compliments of downward vertical motion associated with the progression of the trough and the associated NVA. Highs tomorrow will be similar today save for a much lessened oceanic influence as surface wind turns offshore and the seabreeze remains pinned. Heat index values will be lower however as this windshift brings slightly lower dewpoints. && .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/... As of 3 PM Monday...Expansion of elongated mid-level ridge over the Southeast through mid-week and weak high pressure at the surface will likely keep most of the region dry through Thu night. Weak cold front will be just offshore Wed morning with the front expected to linger through Wed night before dissipating Thu. An isolated afternoon shower or thunderstorm along the sea breeze/Piedmont trough cannot be ruled out. However, coverage would be limited given the unfavorable environment, mainly an abundance of mid-level dry air. Temperatures will run a little above climo with highs in the low to mid 90s and lows in the lower 70s. && .LONG TERM /THURSDAY THROUGH MONDAY/... As of 3 PM Monday...Mid-level ridge weakens and shifts southeast late in the week as surface high consolidates offshore. The increase in moisture along with the decrease in subsidence aloft will lead to increased shower and thunderstorm coverage for the weekend. Early next week a 5h cutoff develops over Nova Scotia with broad 5h trough over the East coast pushing a cold front into the area. -Scattered afternoon showers and thunderstorms Fri through Mon. Storms may lingering into the evening hours. -Temperatures slightly above to above climo through the weekend. -Cold front will drop temperatures back near climo for Mon. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... As of 00Z...A cold front currently over GA will track eastward overnight tonight. Ongoing convection will move over western SC and diminish with a stabilizing BL and entraining dry air ahead of the front. By the time the boundary reaches our area, there could be a few residual showers, but mostly, expect a BKN mid-level deck. Thereafter, westerly winds 5-10 knots and mostly clear skies will prevail; VFR conditions throughout the period. Extended Outlook...Mainly VFR through the period with brief MVFR/IFR conditions from afternoon convection and early morning fog and/or, low stratus. && .MARINE... Tonight As of 1015 PM Monday...Not much if any tweaking needed other than blending current wind trends into the overall fcst scheme. Sig. seas will run 1 to 3 ft with the 3 footers mainly off Cape Fear and Romain respectively. Tonight thru Tuesday Night: As of 3 PM Monday...Southwesterly flow cause by west Atlantic high pressure tonight will give way to increasingly westerly and then northwesterly wind Tuesday into Tuesday night as a very weak front pushes through. The gradient never really picks up as this occurs so a wind speed forecast of 10kt will hold throughout. Waves will remain capped at 2 ft, possibly running a tad lower near shore due to coastal wave shadowing especially by Tuesday night. Weak gradient through the end of the week with surface high overhead slowly shifting offshore will keep east to southeast winds 10 kt or less into the weekend. Might be a slight bump in speeds Sat afternoon as the Piedmont trough becomes a little better defined. Seas around 2 ft through the end of the work week increase to 2 to 3 ft Sat. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ SYNOPSIS...MBB NEAR TERM...DCH/MBB SHORT TERM...III LONG TERM...III AVIATION...21
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1042 PM EDT Mon Jun 24 2019 .UPDATE... Issued at 1042 PM EDT MON JUN 24 2019 A few showers and storms are progressing over southeastern Indiana and central Kentucky. However, the HRRR shows these dissipating by the time they would enter eastern Kentucky. Therefore, have kept our area dry tonight based on this model guidance. The main concern for the overnight will be areas of patchy fog and river valley fog, especially since clouds are clearing a bit faster than originally expected. Have updated Sky Cover to better reflect these trends as well. Since showers and storms are no longer a threat tonight, sent an updated HWO as well as a new ZFP. Other than this, ingested the latest observations and blended into the overnight hours. Current temperatures across eastern Kentucky are in the upper 60s to around 70 degrees in spots. Lows are still on track to dip into the mid 60s by tomorrow morning. Updates have been sent to NDFD and to the web. UPDATE Issued at 825 PM EDT MON JUN 24 2019 The lines of strong to severe thunderstorms have moved into VA and WV. The atmosphere across East KY has stabilized and Severe Thunderstorm Watch 439 has thus been cancelled. Expecting what remains of the shower activity to move out of the state next hour or so, along with thunder chances. Have updated PoPs to reflect these trends and have also removed thunder after 9PM. Due to recent rains and sufficient moisture still present, some river valley fog as well as areas of patchy fog are possible during the overnight. Current temperatures are in the lower to mid 70s, with lows tonight in the mid 60s expected. A new ZFP was recently sent. All updates have also been sent to the web and to NDFD as well. && .SHORT TERM...(This evening through Tuesday night) Issued at 453 PM EDT MON JUN 24 2019 An MCV continues to progress east across the Commonwealth within a mid level trough approaching from the west but well in advance of a cold front entering the Lower OH Valley. Convection is ongoing over the region with strongest cells just southwest of JKL at present. Base velocities in excess of 60kt have been noted with the line segment west of JKL within a reflectivity nub, indicative of QLCS tornado potential and hence the recently issued tornado warnings. The MCV will continue moving east northeast across the region through early this evening with the axis of the 500 mb trough approaching the area tonight and moving east of the region on Tuesday morning. Height rises should follow for Tuesday and into much of Tuesday night as ridging over the Southeast builds into the area. The cold front associated with the mid level trough will move across the area late this evening into the overnight hours moving into VA by dawn. Sfc high pressure will build into the Appalachians to end the period. The main period of concern weatherwise is through around 7 PM as the MCV continues moving east northeast and thunderstorms work across the remainder of the area. The southeast portion of the area has received sunshine so at least strong to damaging wind gusts will remain a hazard with small hail and heavy rain possible. An isolated brief tornado cannot be completely ruled out. Chances for showers and storms will diminish through the evening, though a shower will remain possible until the cold front moves through during the predawn hours of Tuesday. Some fog will also be possible, especially late as winds should diminish, particularly behind the front. High pressure at the surface and aloft should bring gradually decreasing clouds and dry weather on Tuesday. Dry weather should continue through Tuesday night and into the start of the Long Term period. Temperatures will be close to early summer normals. .LONG TERM...(Wednesday through Monday) Issued at 422 PM EDT MON JUN 24 2019 Broad zonal flow will transition Thursday and Friday as a southern stream shortwave trough cuts off across the lower Mississippi Valley and Dixie Alley, competing with ridging attempting to build in from both the Midwest and western Atlantic. Surface ridging across the Appalachians will help to keep the main storm track north of the Bluegrass region through Thursday, with convection also confined farther south near the above mentioned upper wave. Friday afternoon/evening may bring a few showers/storms to the higher terrain near the Tennessee/Virginia borders as a northern stream impulse rotates through the upper Ohio Valley south of the parent low positioned near Hudson Bay. This will help suppress the surface high southeast and allow for enough moisture return to spark a couple of storms. Showers and storms will continue to be a possibility through the weekend as the Hudson Bay low slides southeast across Quebec with cyclonic flow fighting to break down the western Atlantic ridge. Despite the uncertainties in the exact evolution of the synoptic pattern, higher heights and relatively drier air look to bring a return to warmer temperatures with highs in the mid-upper 80s and lows in the mid-upper 60s. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) ISSUED AT 825 PM EDT MON JUN 24 2019 Most of the shower and storm activity has moved east of Kentucky thanks to a passing cold front over the eastern portion of the Commonwealth. Mainly VFR conditions were observed at issuance, but some instances of MVFR were reported as well. Not expecting any more showers or storms for the rest of the TAF period, but some river valley fog is possible overnight tonight. This is primarily due to recent rains and lingering moisture. Have included mention of lowering CIG and VIS to MVFR for all TAF sites tonight. However, the fog is expected to dissipate with the sunrise tomorrow morning. Clouds will decrease through tomorrow morning as well, with mostly sunny skies the main story tomorrow afternoon. Winds will generally be light and variable tonight, but increase to be between 5 and 10 knots from the west tomorrow afternoon. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...CGAL SHORT TERM...JP LONG TERM...GUSEMAN AVIATION...CGAL
Area Forecast Discussion
National Weather Service North Platte NE
625 PM CDT Mon Jun 24 2019 .SHORT TERM...(This evening through Tuesday night) Issued at 332 PM CDT Mon Jun 24 2019 A weak disturbance operating on a cold front dropping through wrn and ncntl Nebraska could produce a small batch of showers and thunderstorms this evening. The HRRR, HREF, RAP and model blend appear to be in very good agreement for scattered showers and thunderstorms affecting the Sheridan county, the Sandhills and ncntl Nebraska. A small cluster of thunderstorms is expected to develop Tuesday afternoon on the Cheyenne Divide. These storms will affect swrn Nebraska Tuesday evening, mainly south of Interstate 80. The NAM, HREF and GFS are in very good agreement for this event. POPs are capped at 30 percent given the compact nature of the convection shown by the models. Winds aloft are still strong Tuesday (30-40kts at h500mb) and this could support strong or isolated severe storms. A rich batch of instability will be lifting northwest through KS (4000+ J/KG MLCAPE) and this could fuel the storms throughout the evening as they move through swrn Neb. The temperature forecast tonight uses the straight guidance blend which is the coolest solution. Bias correction was added to the guidance blend Tuesday and Tuesday night as warmer temperatures and south winds will develop, especially Tuesday night. .LONG TERM...(Wednesday through Monday) Issued at 332 PM CDT Mon Jun 24 2019 The thunderstorm chances (30-40 percent) Wednesday evening are a bit more widespread for this forecast as instability has advanced north into wrn and ncntl Nebraska. Winds aloft at 500 mb are weak at 20- 25kts and the cap is still relatively weak (12C at h700mb). This would support a multicell outflow dominant storm environment perhaps lasting well into the evening as a modest 30-35kt low level jet develops. The NAM develops eastward moving storm complexes over nern Colo, the Laramie Range and Pine Ridge. The rest of the thunderstorm forecast is generally isolated as temperatures at h700mb warm to around 14C. Winds aloft weaken further to less than 20 kts at h500mb. Stronger winds, around 30kts, are available at h300mb if storm updrafts become sufficiently deep. A weak cold front may move through next Monday. The models suggest a chance of thunderstorms ahead of the front Sunday night. The model blended forecast concept has nudged high temperatures Thursday through Sunday a degree or two higher with more highs in the 90s. Sfc low pressure will remain anchored on the nrn high Plains and this should provide a more or less continuous moisture feed from the South. The NAM suggests dew points in the mid 60s to lower 70s Thursday which could become common Friday through Sunday. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 625 PM CDT Mon Jun 24 2019 VFR will continue through the forecast period for western Nebraska terminals. A few rain showers or thunderstorms will cross north central Nebraska late this evening, possibly affecting KGRN, KVTN, KANW, KONL. Winds turn light and variable overnight as the sky returns to mostly clear lasting through the day on Tuesday. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...CDC LONG TERM...CDC AVIATION...Roberg
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1039 PM CDT Mon Jun 24 2019 .SHORT TERM...(This evening through Tuesday night) Issued at 256 PM CDT Mon Jun 24 2019 Upper level trough moving overhead today as evident by afternoon satellite imagery paired with RAP 500mb heights. Scattered showers with isolated thunder were working eastward along and to the east of the trough axis this afternoon. In western MN, showers had ended skies were beginning to clear, with mainly just high clouds left, along with some scattered cumulus. The trough axis will continue to swing east as it takes on a negative tilt with time over WI. The showery activity across eastern MN and western WI will come to an end by this evening as the trough axis moves east of our area, leaving us with dry northwesterly flow. Zonal flow will develop in the wake of the departing trough tomorrow, so partly cloudy skies with temperatures likely warming into the lower 80s is expected. A shortwave trough is expected to move east across North Dakota overnight, and affect northern MN tomorrow. There could be increased cloud cover for parts of central MN from this, but most of the area will see mostly sunny skies tomorrow. Clear skies continue tomorrow night as a surface ridge axis moves through the area. .LONG TERM...(Wednesday through Monday) Issued at 256 PM CDT Mon Jun 24 2019 Not much change to the forecast in the long term with the main focus being the return of more summer-like warm and humid temperatures, as strong ridging builds into the upper midwest beginning midweek. Heat will build through the week as the ridging amplifies overhead, with 850 mb temperatures increasing to around 25 C by the weekend. Widespread highs in the 90s are expected by Friday, with the upper end of guidance showing the potential for some mid-upper 90s across western Minnesota over the weekend. Overnight lows look to be quite warm as well, in the mid 60s to low 70s, and look to be even warmer in the core of the Twin Cities metro with the urban heat island effect. Dewpoints will also be on the increase as well, with much muggier air advecting dewpoints near 70 degrees into the region by Thursday. Model show dewpoints increasing even higher into the mid- upper 70s over the weekend, and in in a typical summer we would see a boost to this gulf moisture due to evapotranspiration from mature crops in the fields. However, believe these more extreme dewpoints are overdone after accounting for the very late planting season. Still, dewpoints around 70 and temperatures in the 90s will still allow for heat indices to approach 100 this weekend so heat precautions should be considered for any outdoor activities. Confidence in the precipitation forecast still remains low, but a couple periods stand out as our better chances. The first comes Wednesday night into Thursday as the low-level jet ramps up and brings our first surge of warm advection into the region. Forcing aloft remains limited to a weak shortwave which may only skirt southern Minnesota, so PoPs remain in the lower 30-40% range. MUCAPE values increase to 2000-3000 J/kg and effective bulk shear values look to approach 30 kts so some more organized and stronger storms look possible. Instability will remain high through the weekend, but strong capping aloft and the jet nosing well north into Canada should limit our precipitation chances overall for Friday/Saturday. Can`t rule out an overnight MCS developing and riding mesoscale boundaries into the area as well, but predictability is too low at this range. Finally, precipitation chances look to increase again Sunday into early next week as the ridge flattens and drops the the jet stream back over the region. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) Issued at 1039 PM CDT Mon Jun 24 2019 Storms coming in on a shortwave over the Dakotas have run out of instability and expect this showers to be mostly dissipated by 6z, with nothing more than accas expected as this wave pushes east tonight. Still anticipate deep mixing Tuesday, with west winds gusting up around 25 kts, with the strongest winds in central MN. KMSP...No additional concerns. /OUTLOOK FOR KMSP/ Wed...VFR. Winds SW 5-10 kts. Thu...VFR. Chc MVFR/tsra. Winds SSE 5-10 kts. Fri...VFR. Winds SE 5-10 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. && $$ SHORT TERM...SPD LONG TERM...ETA AVIATION...MPG
Area Forecast Discussion
National Weather Service Marquette MI
843 PM EDT Mon Jun 24 2019 .SHORT TERM...(This evening through Tuesday) Issued at 427 PM EDT MON JUN 24 2019 Water vapor imagery and RAP analysis show a vigorous shortwave beginning to take on a negative tilt as it lifts thru the Upper Mississippi Valley. At the sfc, low pres trof extends across western Upper MI from e side of the Keweenaw Peninsula s to around Watersmeet. Increasing deep layer forcing ahead of the shortwave is beginning to support an expansion of shra and some isold thunder ne from WI into central Upper MI. Fortunately, abundant low-level moisture and resulting cloud cover has kept instability in check today. Latest SPC mesoanalysis shows MLCAPES up to around 500j/kg and MUCAPE into the 500-1000j/kg range. Upstream, next shortwave of interest is over MT, and this feature will play a role in the weather here on Tue as it may lead to strong to svr storms. Expect shra to continue expanding over the next several hrs and spread e and ne in association with shortwave lifting across the Upper Great Lakes. Expect some locally hvy rainfall. After the overall dry conditions that have prevailed this month across the fcst area (month to date pcpn is running under 50% of normal over the w half of Upper MI with a good portion under 25% of normal), the rainfall is needed to alleviate the short term dryness. Unfortunately, heavier rainfall will miss some of the driest areas over the w. Svr risk appears to be very limited based on current instability and widespread cloud cover limiting any additional buildup of instability. In addition, deep layer shear has fallen off to under 25kt this aftn. Shra will wind down overnight, but may linger for most of the night over the e in cyclonic flow immediately following passage of the low-level trof. Fog is likely present over western Lake Superior after the rainfall of the last 24hrs, and this fog will affect areas near the lake thru the evening under wnw winds. Fog may expand inland for a time toward and after sunset. Active late aftn is likely on the way Tue. Shortwave currently over MT will move across northern MN Tue aftn and will reach Upper MI Tue evening. W and WNW mid-level flow are the most favorable regimes for warm season strong to svr storms in Upper MI, and westerly flow will be present on Tue. In addition, low-level wind fields will be westerly, supporting better low-level convergence as aftn winds develop a lake breeze component off the Lakes. This is especially so over the e half of the fcst area. Consensus of 12z guidance is for MLCAPES to increase to around 1000j/kg in an environment of 30-40kt of deep layer shear. Expect sct shra/tstms to develop after 18z. However, Keweenaw likely won`t see any shra under stabilizing westerly winds off Lake Superior. Hail will be the main risk with wetbulb zero heights favorably positioned in the 8-10ft layer. Dry mid-levels are missing to enhance wind risk, but strong winds still a possibility. Will be warm, summer day with highs mostly in the upper 70s/lwr 80s. Will also be breezy with mixed layer winds supporting gusts to 20-25mph and at times 30mph. .LONG TERM...(Tuesday night through Monday) Issued at 433 PM EDT MON JUN 24 2019 The active convective weather continues into this forecast period, with a brief break likely for most in Upper Michigan on Wednesday, save a slight chance of thunderstorms in the east (low confidence in this coming to fruition). From Thursday into the weekend, the U.P. will linger in an unsettled pattern that consists of weak shortwaves riding along the periphery of mid- to upper-level ridging, increasingly amplifying by the end of this weekend. Given this type of setup, longer-range models are struggling to come into agreement on the finer details, as is typical, yielding nearly daily PoPs, but only due to the sporadic nature of the expected activity. Summer has finally arrived (and not just officially) as temperatures steadily rise and linger in the 70s (near the lakeshores) and 80s (more widespread, inland) for highs each day. Lows will respond accordingly, with widespread 50s to around the 60 degree mark closest to the WI border. As already alluded to, instability will become increasingly available as well, allowing for those aforementioned thunderstorm chances to ramp up throughout this forecast period. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 833 PM EDT MON JUN 24 2019 A low pres system lifting thru the Upper Great Lakes produced shra and a few tsra this evening/early evening, mainly impacting KSAW. Coverage of shra will be more isolated to the w, so only VCSH was mentioned in fcst at KIWD/KCMX. At KIWD conditions have already improved to VFR as somewhat drier air has worked into the area. KCMX will see LIFR to possibly VLIFR conditions into the evening as cool/moist marine layer upslopes to that terminal under wnw winds, but then influx of drier air will allow for improvement to VFR late tonight. KSAW should see prevailing MVFR conditions into this evening with the pcpn, but as winds shift to downslope westerly direction overnight drier air will result in rapid improvement to VFR overnight. Breezy w winds gusting to 20-30kt are expected at all terminals on Tue. VFR conditions will likely prevail thru the day on Tuesday but an upper disturbance moving in late afternoon will bring an increasing chance for shra and tsra at KIWD and KSAW. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 427 PM EDT MON JUN 24 2019 Sfc low pres will lift ne of Lake Superior tonight. Until the low passes, se winds over the e half of Lake Superior will continue to gust to 15-25kt, and up to 30kt at high obs platforms. As the low lifts ne, westerly winds gusting to around 20kt will develop from w to e. High obs platforms could see gusts to 25-30kt. Westerly winds will continue Tue, mostly in the 10-20kt range though gusts to 20- 25kt are expected across the w half of the lake, especially around the w and n side of the Keweenaw. Winds will be slightly weaker on Wed, then light on Thu as high pres ridging arrives. Light winds will continue on Fri. Areas of fog have developed on Lake Superior. This fog may be locally dense tonight, but the fog will clear out from w to e late tonight and Tue. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... Dense Fog Advisory until 11 PM EDT this evening for LMZ221-248- 250. && $$ SHORT TERM...Rolfson LONG TERM...lg AVIATION...Voss MARINE...Rolfson