Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 08/03/17

Area Forecast Discussion
National Weather Service La Crosse WI
630 PM CDT Wed Aug 2 2017 .SHORT TERM...(This evening through Friday) Issued at 302 PM CDT Wed Aug 2 2017 A weak cold front has settled south of the area, although with little change in airmass. With MLCAPEs of 1000-2000 J/kg and minimal capping, scattered showers and storms will continue to develop this afternoon, highest chances in central/western Wisconsin. With shear very weak, storms will remain disorganized with severe storms unlikely. A few showers/storms could linger tonight with increasing southerly flow and warm advection. Of more significance will be an intense upper shortwave trough approaching on Thursday. Initially as stronger deep layer forcing increases Thursday morning, a band showers/storms from overnight may make it eastward into the area, although high-res guidance differs somewhat on the timing of this precip, a line of showers/storms may progress into the area by around sunrise. With little capping in place, additional showers/storms are expected at times Thursday along and ahead of the front. With potential for widespread clouds, the degree of destabilization remains a question mark. However, deep layer shear increasing to around 40 kts combined with the strong forcing could result in some strong to severe storms ahead of the front, with winds/hail the primary threats. A tornado could not be ruled out near the surface low/warm front. The magnitude of the severe threat will depend on whether any clearing occurs within the warm sector, how far north the warm sector/surface low reaches, and the timing of the front. At this time, southwest Wisconsin appears to have the greatest chances for severe storms. However, there are still some differences in the low track, with the GFS farthest south, and the ECMWF/GEM maintaining a more northerly track across central Wisconsin. The strongest forcing/deformation zone looks to remain north of I-90, where the more widespread rain is forecast, with amounts of 1-2 inches possible in some areas. See the hydro section for more details. Cool and showery weather is expected behind the front tomorrow night. Friday will be more fall-like with breezy northerly winds and temps likely holding in the 60s to low 70s. Some showers could linger into Friday behind the departing surface low. Clearing is possible through the day as subsidence develops behind the upper trough, but it may be tough to scour out the residual lower level moisture/clouds. .LONG TERM...(Friday night through Wednesday) Issued at 302 PM CDT Wed Aug 2 2017 A seasonably cool period will persist this weekend into next week under northwesterly flow aloft with chances for scattered showers or storms as upper level energy rotates through the broader trough. The 02.12Z GFS is deeper and farther south than the ECMWF/GEM with an upper low dropping across the region later Sunday/Sunday night, so details remain unclear. Some gradual warming is expected early next week, but temps should remain near to slightly below average. Although timing of the embedded waves becomes more uncertain by early next week, a period of drier weather is expected early next week under surface high pressure. Additional showers/storms are possible by the middle of next week with models suggesting another upper low and cold front approaching the region. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 630 PM CDT Wed Aug 2 2017 The remaining convection this evening should remain to the east of both airports before is dissipates after sunset. An area of MVFR ceilings formed last night over the U.P. of Michigan and has survived through the day over northeast Wisconsin but with ceilings coming up to VFR. This area of moisture is shown by the 23.18Z NAM and 23.21Z RAP to work west through the night and expand underneath the inversion that will form after sunset. This is expected to bring the clouds with MVFR to IFR ceilings into both airports overnight. Some slight improvement in ceiling heights should occur Thursday morning, but look for the MVFR conditions to remain through the rest of the day. Showers and a few storms expected to move in Thursday morning and then continue for most of the day as a short wave trough over North Dakota drops southeast across the area. The instability looks very limited for both airports so should primarily be showers with a few embedded storms. Some of the hi-res models are suggesting a band of showers and isolated storms could move through early Thursday morning followed by a break with more activity for the late morning and afternoon. If this continues to be a trend, will attempt to detail it with later forecasts. && .HYDROLOGY... Issued at 302 PM CDT Wed Aug 2 2017 A strong low pressure system will bring periodic showers/storms later tonight into Thursday night. Rainfall amounts of 1 to perhaps 2 inches are possible, mainly near or north of I-90, where precipitation may be more widespread. However, locally heavy rain could also occur farther south with any more persistent thunderstorms. However, at this time, flood risk still appears low given the expected progressive nature of the storms. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ SHORT TERM...JM LONG TERM...JM AVIATION...04 HYDROLOGY...JM
Area Forecast Discussion
National Weather Service Taunton MA
1007 PM EDT Wed Aug 2 2017 .SYNOPSIS... Scattered shower and thunderstorm activity will continue through the remainder of the week. A cold front will cross the region Saturday that may bring another round of scattered showers and thunderstorms. A few strong storms are possible. Behind the front, expect beautiful late summer conditions on Sunday with low humidity. Unsettled weather may return early next week in the form of more scattered showers and thunderstorms. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... Current trends are on the quiet side as any leftover thunderstorms have dissipated due to the lost of heating. Still cannot rule out a few spot showers but believe that over trend is low and thus have gone towards dry pops for now. Believe the latest HRRR is to aggressive in regenerating precip. Otherwise the focus turns towards the fog potential for tonight. Cloudy skies currently, will eventually clear out over the next several hours. This will result in radiational cooling as winds will be light. Locations where the heavy rain has fallen, as well as higher dewpoints will have the best shot for lower vsbys. Will have to watch closely for dense fog. Aside from a few minor adjustments, the overall forecast remains on track for this evening. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... Thursday... Scattered showers and thunderstorms mainly over N/W MA and CT. Low clouds and fog dissipating during the morning hours with the early-August sun. Anticipating the burn-off towards the SE coast, low clouds lingering the longest in and around the Newport RI to New Bedford MA region. Heights rising within the mid-upper levels out ahead of a stronger vortmax in associated with deeper mid- level troughing across the Great Lakes region. A bit more of a cap across the region, limiting shower and thunderstorm activity, however given the moist, unstable environment still in place, some activity is expected, the area of greatest threat to the N/W away from the more onshore, stable marine air, mainly atop the high terrain with anabatic, convergent flow up the slopes. Heavy rain the main threat given the weak shear and mean wind profile. Storms likely once again to be the pulse-type and slow moving given the weak steering flow. Thursday night... Convection dissipating again, expect the return of low clouds and fog. Clearing into the evening, anticipating that all the low clouds along the S-shore dissipated or become scattered, given the low level moist profile and nocturnal cooling, low clouds and fog develop once again. Higher dewpoint air over much of the region, feel there is a risk of low clouds and fog over a majority of S New England. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... Highlights... * Typical summer warmth and humidity Friday and Saturday * Scattered afternoon and evening showers/thunderstorms Friday * Another round of showers/thunderstorms with a cold front during Saturday, a few may be strong * Heat and humidity break Sat night into early next week Overview... Main H5 steering pattern across continues to signal an eastern Pacific/Alaska high amplitude ridge with responding downstream trough from broad cutoff H5 low across Hudson/James Bays through Ontario to the mid Mississippi valley. Will start off with S-SW winds and warm, humid conditions. With cold front well W of the region, may see diurnal showers/thunderstorms during Fri across central and western areas. The upper pattern remains relatively progressive, so models continue to signal cold front moving steadily E during Sat, but appears most of the energy will remain N of the region as the short wave swings NE across upstate NY into Quebec. As the short wave lifts out of the region late this weekend, generally a mainly zonal flow will bring dry and briefly cool conditions. Another short wave may push E-NE across the Great Lakes early next week. A weak surface reflection may push E, but timing and track are in question due to wide model solution spread. Overall, however, pattern looks to remain progressive through the middle of next week. Details... Friday... With broad, diffluent SW flow aloft, the cold front should remain well W of the region closer to the mid level trough. Also noting low pressure off the mid Atlantic coast which should slowly pass well SE of the region. With general instability across the region, expect scattered afternoon/evening showers and thunderstorms to develop. PWATs generally 1.5 to 1.7 inches, so may see some locally heavy downpours. Scattered showers may linger Fri night across central and western areas ahead of approaching front. SW winds gusting up to around 20-25 mph along the S coast. Away from the S coast, temps will top off in the lower-mid 80s. Saturday-Saturday night... Cold front steadily pushes E during this timeframe. Best shot for showers/thunderstorms will occur during the day Sat, especially across western areas where likely POPs remain in place, with scattered activity further E. Good instability noted, with SLIs from zero to -2 and K indices in the lower 30s. Also noting PWATs in the 1.7 to 1.8 inch range across western areas, so may see spotty heavy downpours during the day. Back edge of precip should push E starting Sat evening across the CT valley, with a few lingering thunderstorms through around midnight across the E. Expect improving conditions after 06Z- 08Z across E Mass/RI as drier air works in. Sunday-Monday... Cold front well offshore by Sunday morning, then broad high pressure works in. This will be cooler conditions especially across the interior. H85 temps will be down to +10C to +12C Sunday morning, coolest across the E slopes of the Berkshires where high temps will only reach to around 70 (about 10 degrees below normal). Temps will range to 75-80 across the coastal plain. On Monday, the high will shift offshore in fast nearly progressive mid level flow. Some question on timing of next approaching low, with leading edge may push into western areas Mon night. Tuesday-Wednesday... Low confidence for Tuesday as low pressure may pass across the region. Carrying chance POPs for now with timing and exact track issues in place. Low may push offshore by Tue night, then another high may approach Wed. For now, have continued with below normal temps both Tue and Wed. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Thursday Night/... Tonight...Moderate confidence. SHRA/TSRA dissipate after sunset. VFR mostly however expect IFR-LIFR CIGs and VSBYs to develop once again. Higher confidence for the lower CT River Valley and interior SE New England terminals. Light S winds overall. Thursday...Moderate confidence. IFR-LIFR CIGs and VSBYs erode towards the S-coast, lingering possibly into the midday hours for places like UUU-EWB. SCT SHRA/TSRA develop over the N/W interior, mainly across the high terrain. TEMPO MVFR-IFR with any wet-weather. Otherwise VFR with breezy S winds, gusts up to 20 kts. Thursday night...Moderate confidence. SCT SHRA/TSRA dissipate into evening. VFR initially again but expect IFR-LIFR CIGs and VSBYs to develop, more widespread over S New England terminals into Friday morning. Light S winds. KBOS Terminal...VFR through the night. May have to watch for MVFR cigs. KBDL Terminal...VFR to start. Anticipate patchy fog and MVFR to brief IFR VSBYS in vicinity of terminal from around 09Z through 12Z. Outlook /Friday through Monday/... Friday...High confidence. Mainly VFR. May see sct SHRA/TSRA across N central and western areas Fri afternoon/evening, then taper back to SHRA across the CT valley Fri night. Patchy late night/early morning fog with local MVFR-IFR VSBYS. Saturday...Moderate to high confidence. Sct-numerous showers/sct TSRA with local MVFR-IFR conditions. Some +SHRA possible over central and western areas through early afternoon. Leftover patchy early morning fog. Light S-SW winds shift to W across central and western areas Sat afternoon. Saturday night-Sunday...Moderate confidence. Leftover SHRA/TSRA over central and eastern areas Sat evening, should push offshore by 04Z-05Z. Otherwise, VFR conditions. W-NW winds 5-10 kt. Sunday-Monday...Moderate confidence. VFR conditions Sunday. Scattered showers move from W-E during Monday, but timing in question. Local MVFR CIGS/VSBYS. && .MARINE... FORECASTER CONFIDENCE LEVELS... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Thursday Night/...High confidence. Small boats along the S waters should tread cautiously for the next few days as likely with daytime mixing and subsequent sea breezes, winds especially within bays and sounds will likely gust 15 to 20 knots with sustained winds around 10 to 15 kts. Seas remaining below 4 feet but expect 2 foot seas within the inner harbors and bays. Tonight... Storms dissipated. Some low clouds and fog conditions are possible along the near shore waters. Otherwise light S winds. Thursday into Thursday night... Breezy S winds up to 20 kts during the day. The return of low clouds and fog along the near-shore possible overnight. Outlook /Friday through Monday/... Friday...High confidence. May see S-SW wind gusts up to 25 kt and seas to 4 ft east of the Merrimack River Fri afternoon/evening. Otherwise expect winds and seas below small craft criteria. Locally reduced visibilities in patchy late night fog. Saturday...Moderate confidence. S-SW winds will shift to W-NW Sat night. Gusts up to around 20 kt. Scattered showers/isolated thunderstorms possible Sat afternoon/evening. Conditions should improve around or after midnight. Locally reduced visibilities in patchy late night fog. Sunday-Monday...Moderate to high confidence. Dry conditions Sunday. Light W-NW winds. Remaining dry Monday morning through midday, then scattered showers move across from W-E through Monday night. Local visibility restrictions in showers and patchy fog. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...Sipprell/EVT NEAR TERM...Dunten/EVT SHORT TERM...Sipprell LONG TERM...EVT AVIATION...Sipprell/EVT MARINE...Sipprell/EVT
Area Forecast Discussion
National Weather Service Burlington VT
735 PM EDT Wed Aug 2 2017 .SYNOPSIS... Above normal temperatures and deeper moisture will set the stage for isolated to scattered afternoon and evening showers and thunderstorms today and Thursday. Better chances for showers and thunderstorms will exist Friday into Saturday as an upper level trough of low pressure slowly moves across the region. Cooler and drier weather is expected on Sunday. && .NEAR TERM /THROUGH THURSDAY/... As of 630 PM EDT Wednesday...The forecast remains in overall good shape as we progress into the evening hours. With relatively high freezing levels (12-13 kft) and weakly forced flow aloft, convection today was unorganized and pulse in nature with a few briefly stronger updrafts that plausibly led to gusty winds and some small hail here and there - nothing too much above "garden variety" stuff. With loss of heating activity is steadily on the downturn and have leaned in the direction of hourly HRRR pops through 9-10 pm or so, after which we should see a mainly dry overnight period. Most concentrated lingering activity through sunset should be across the Adirondacks where a brief heavier downpour will remain possible. Some variable high clouds from this afternoon`s convection continues to float around here and there, but this should trend bodily toward partly cloudy/mostly clear skies later tonight along with patchy fog in favored locales - all covered in current forecast quite well. Have a great evening. Prior discussion... Still dealing with an environment conducive to pulse storms late this afternoon with temperatures in the 80s and dew points in the lower to mid 60s. This combined with 850/500 millibar lapse rates approaching dry adiabatic and we have enough instability for isolated pulse storms. Flow aloft is very weak and thus as we get to sunset...we lose the instability and any showers or storms come to an end. Should be quiet overnight with some fog forming in the favored valley locations. Lows will be in the 60s with some 50s in the mountains. Thursday is looking very similar to today. Highs in the 80s...dew points in the 60s...and steeper mid level lapse rates to produce sufficient instability for pulse storms to develop. Activity will be terrain driven and any mesoscale boundaries. Flow aloft remains weak and once we lose the daytime heating...showers and storms will come to an end. Will continue to word the activity as isolated to scattered showers and storms. Brief heavy downpours and gusty winds would be the main threat if any of the storms get organized...which has a low likelihood. && .SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/... As of 337 PM EDT Wednesday...Thursday night will be similar to Wednesday night with any convection quickly coming to an end and clear skies and light winds allowing for some fog in the favored valley locations. Composite analysis of the convective potential for Friday looks different than Wednesday and Thursday. Upper trough moves across the Great Lakes but still remains well west of the area. This will keep more favorable deep layer shear out across the eastern Great Lakes and into western New York and parts of northern New York. At this time feel in our area the Saint Lawrence Valley will see sufficient deep layer shear moving over the top of the favorable instability that is expected to develop with highs in the 80s and dew points once again in the 60s. Could see some organized storms late in the day and will have to keep an eye on this situation as there may be an increased hail and wind threat. This upper trough is slow to move east so we lose the instability Friday night when the stronger shear finally moves over the area. Feel the threat for showers and some storms will exist...but stronger convection may be limited. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... As of 352 PM EDT Wednesday...Trends in the long term continue to slow the timing of the front that comes through the weekend. I trended the forecast towards the EC supporting showers across the eastern Dacks Saturday morning and then brings the showers into Vermont later in the day. The PWATS do surge but there`s a only small window in which we could see convection. However the forcing isn`t collocated in with the axis of heaviest precip so I`m not too bold on the idea of significant weather. High pressure builds into the region for Sunday leading to cooler and drier conditions which brings our temperatures back to near normal. With northwest flow I did keep the idea of some lingering showers as there may be some orographic lift helping showers to stick around. Towards Monday afternoon, an upper level low will dig into the the Great Lakes region and bring an surface low pressure system up the Saint Lawrence valley. This should bring widespread showers and thunderstorms Monday into Tuesday. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... Through 00Z Friday...Isolated storms, mainly in northern NY winding down this evening and have TAF sites dry through the overnight hours. Expect KMPV/KSLK to fog in again tonight as last night with good radiational cooling in light winds and clearing skies, and dewpoints in the mid 60s. More of a LIFR fog threat at KSLK where a brief thunderstorm this afternoon dropped a quick 0.17 inch of rain to wet the ground. Any LIFR fog & stratus to dissipate around 12z. Thursday afternoon similar to today with moist unstable airmass and weak forcing, focusing afternoon thunderstorms again mainly in the higher terrain. Went predominately with VCSH for now with chances in the outer period of the TAF. Light southerly wind to become near calm overnight except KRUT where nocturnal drainage wind from the southeast sets up. Outlook... Thursday Night: VFR. Isolated SHRA...Isolated TSRA...Patchy FG. Friday: VFR. Breezy. Scattered SHRA...Scattered TSRA...Patchy FG. Friday Night: VFR. Breezy. Scattered SHRA...Isolated TSRA. Saturday: VFR/MVFR. Breezy. Likely SHRA...Slight Chance TSRA. Saturday Night: VFR. Slight Chance SHRA...Slight Chance TSRA. Sunday: VFR. NO SIG WX. Sunday Night: VFR. NO SIG WX. Monday: VFR. Chance SHRA. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...Evenson NEAR TERM...Evenson/JMG SHORT TERM...Evenson LONG TERM...Deal AVIATION...Hanson
Area Forecast Discussion
National Weather Service Cheyenne WY
907 PM MDT Wed Aug 2 2017 .UPDATE... Issued at 901 PM MDT Wed Aug 2 2017 Latest radar loop was showing a few showers and isolated thunderstorms developing in southwest Wyoming. These showers appear to be weakening, but should continue their trend east- southeast through midnight before dissipating as the main upper level jet energy tracks southeast into northern Colorado. Meanwhile, the low level flow is progged to turn east tonight which will allow for the low level moisture to increase along the foothills and higher elevations tonight. Both the HRRR and NAM3km are indicating this potential. As a result, we introduced some areas of drizzle, low clouds and fog in the morning. The main concerns will be along I-80 near the summit to near Cheyenne. UPDATE Issued at 715 PM MDT Wed Aug 2 2017 Latest satellite loop was showing the clouds clearing out over the forecast area due to good subsidence building in. As a result, we removed much of the POP`s and cloud cover from the forecast this evening. && .SHORT TERM...(This evening through Friday) Issued at 240 PM MDT Wed Aug 2 2017 Just a few showers along with a weak storm or two over the higher mtns so far this afternoon. Cold front now over east-central Wyo into the northwest Neb panhandle is moving south and should clear southern parts of the CWA by early this evening. See little convection now with less instability and with better convergence pushed east along a pre-frontal trough over western Neb. Best area late this afternoon looks to be over my southeast Panhandle counties. Could still see some showers later tonight across southeast Wy as a shortwave moves southeast over the area and interacts with some surface upslope flow. Some fog also possible later tonight into Thursday morning over far se Wy near the Laramie Range. Thursday looking mainly dry and cooler after some lingering morning showers near the Colorado border. Max temps should be in the 60s and 70s with plenty of cloud cover especially near the Laramie Range. The surface high moves into the southern plains Thursday night into Friday with return flow allowing for warmer temperatures. Some convection possible Friday afternoon as instability increases and another shortwave approaches from the northwest. .LONG TERM...(Friday night through Wednesday) Issued at 240 PM MDT Wed Aug 2 2017 Strong shortwave trough in NW flow aloft will track across the area Friday night into early Saturday. Good moisture return ahead of the wave along with steep lapse rates aloft will likely lead to convection developing and possibly continuing into the night time hours Friday night. One or two strong storms are possible with hail/gusty winds with deep layer shear around 40kt Friday evening and overnight. Area remains in cool NW flow aloft through early next week. Models indicate various disturbances tracking SE through the area during this time which will maintain chances for afternoon and evening convection. Temperatures will be a bit on the cool side of normal especially Sunday with 700mb temps around 2 std deviations below normal per the NAEFS. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 528 PM MDT Wed Aug 2 2017 High pressure will continue to build south through the northern Plains tonight into tomorrow. This will bring quite a bit cooler conditions to the area. Cannot rule out an isolated storm or two along the Laramie Range, but this activity should diminish before sunset. Otherwise, there is some potential for mvfr ceilings to develop across some of the taf sites late tonight with the best chance of low ceilings near CYS and LAR. && .FIRE WEATHER... Issued at 240 PM MDT Wed Aug 2 2017 Decent cold front for this time of year will move south across much of the area through this evening with some showers and maybe a couple storms behind it. Much cooler over the plains Thursday then warming back up Friday into the weekend. Overall fire weather concerns will remain low though it may be a bit breezy out west Friday afternoon with min humidities around 20 percent. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ UPDATE...REC SHORT TERM...RE LONG TERM...DEL AVIATION...REC FIRE WEATHER...RE
Area Forecast Discussion
National Weather Service Hastings NE
710 PM CDT Wed Aug 2 2017 .UPDATE... Issued at 710 PM CDT Wed Aug 2 2017 Just published a substantial fcst update to drastically cut POPs (chance for tstms) tonight and decrease cloud cover. All the QG forcing is with the upr trof over the Dakota`s. So that leaves tstm development solely tied to daytime heating and the weak convergence associated with the sfc trof that extends from Wrn Neb into Ern CO. It just isn`t enough to initiate many tstms. Therefore...they can`t form a common cold pool and perpetuate themsevles into the night. The 22Z HRRR finally has a better handle on this situation. There could be a few isolated small shwrs (possibly with some thunder) that develop overnight...but only need a 20% POP to cover that. Most locations will remain dry this eve and tonight. UPDATE Issued at 632 PM CDT Wed Aug 2 2017 We cont to monitor tstm potential as we head into the evening hrs. Convective mode has been cellular out to the W. That is not good for seeing widespread tstms (and needed rain). This could turn out to be a hit-or-miss event with only a small number of small storms (with most getting missed). This is also bad for rain as isolated storms have a better potential to die off with loss of heating vs. a squall line with a well-established cold pool that can perpetuate itself. If more storms don`t form (and form quickly)...this could be a disappointing event for those that want/need rain. Most locations E of Hwy 183 will remain dry...and even those W of Hwy 183 will only see an isolated storm or two. Suffice to say we may be overdone on pcpn chances this evening/ tonight. If current trends cont...some substantial changes will be needed. && .SHORT TERM...(This evening through Thursday) Issued at 352 PM CDT Wed Aug 2 2017 The main forecast concerns for the short term is the cold front moving through and the associated precipitation chances. Cloud cover has increased associated with a MCV moving across central Nebraska. This cloud cover has kept temperatures a bit cooler in central Nebraska. Embedded in this cloud cover is a few light rain showers. Further west, skies have cleared and a few storms have developed and could develop over the next few hours. The high-resolution short-term guidance has been fairly consistent with this light activity this afternoon and the secondary more potent thunderstorm activity along the cold front this evening. Taking an average of the guidance timing, think the best chances will be for the convective line to approach the west/northwest portions of the area around 23-01z and move southeast from there. The line is then expected to move into KS and out of the area by Thursday morning. With modest instability and shear, some storms could be strong to severe with the main threat being damaging wind gusts to 60 mph and quarter size hail. After the line of storms moves through, winds will switch to the northwest and skies will clear. Overnight lows will be low 60s and highs on Thursday, as surface high pressure builds in, will be in the 70s. .LONG TERM...(Thursday night through Wednesday) Issued at 352 PM CDT Wed Aug 2 2017 Northwesterly flow persists through the remainder of the forecast. Surface high pressure will slide eastward on Friday, and high temps will stay in the below normal 70s. The next more potent wave will approach on Saturday which increases precipitation chances for Saturday and Saturday night. There are some discrepancies in how this wave/front will move through the region which could push some of the precipitation into the Sunday time frame as well. High Pressure will build in again behind this wave for the work week. With an upper disturbance rotating around north of the Great Lakes the upper flow will become more zonal and another front threatens the area with a chance for precipitation on Wednesday. Highs will be cooler than normal, in the 70s and 80s through the remainder of the forecast. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Thursday) Issued at 632 PM CDT Wed Aug 2 2017 Significant Wx: Potential for brief IFR +TSRA 02Z-06Z then MVFR CIGs Thu AM. Tonight: VFR except during a window when +TSRA are possible from 02Z-06Z could result in brief IFR VSBYs. The amt of cloud cover and CIGs behind the TSRAs is uncertain...but VFR conds are expected. Lgt and vrbl winds except near TSRAs. Confidence: Medium Thu: MVFR CIGs should invade around sunrise with bases gradually lifting to 4K by midday. NNW winds 11-16 kts. There could be some gusts up to 25 kts...but that`s uncertain due to model disagreement. Confidence: Medium && .GID WATCHES/WARNINGS/ADVISORIES... NE...None. KS...None. && $$ UPDATE...Kelley SHORT TERM...Billings Wright LONG TERM...Billings Wright AVIATION...Kelley
Area Forecast Discussion
National Weather Service Houston/Galveston TX
900 PM CDT Wed Aug 2 2017 .DISCUSSION... Overall radar imagery shows a smattering of showers around and lingering light rain. This is expected to continue overnight as jet streak over N Texas on water vapor imagery moves towards E Texas tonight. CAMs and even synoptic models show another round of convection along the Upper Texas Coast around 08Z to about 16Z Thursday morning. Latest HRRR runs keep most of the convection off the coast but still leary of synoptic models showing precip developing fairly far inland. Trough axis is not expected to push through until late morning to early afternoon so quite possible to have thunderstorms re-develop given precipitable water values around 2 to 2.4 inches. That kind of moist airmass does not take long to recover as long as there is at least some day time heating with breaks in the clouds. Heavy rainfall threat will still be there given the amount of moisture but will require these isolated stronger storms that can utilize 1500 J/kg of CAPE to produce the higher rain rates. Overall activity tomorrow should be less in coverage than today, but still expecting scattered coverage by late afternoon with enough recovery. Overpeck && .PREV DISCUSSION... /ISSUED 628 PM CDT Wed Aug 2 2017/ AVIATION... All remaining thunderstorms have pushed off to be over the nearshore Gulf waters, leaving patches of showers across Southeast Texas. New TAFs reflect this downturn in activity, gliding showers at area sites through the evening. Overnight, the guidance hits ceilings relatively hard, but given the very early start to new showers overnight even far inland, think the models are being a bit aggressive. I keep SCT decks at MVFR heights, but think ceilings will remain higher at this time. Tomorrow, the base of the upper trough will be swinging through, giving us another chance at showers and storms. Given model trends, have delayed the onset of VCSH and VCTS slightly, but still hold onto potential for another less intense round of cells to fire. Luchs PREV DISCUSSION... /ISSUED 305 PM CDT Wed Aug 2 2017/ DISCUSSION... Scattered to numerous showers and thunderstorms moved across SE TX today and for the most part, the storms behaved themselves with locally heavy but not excessive rainfall. PW values remain high tonight with values remaining around 2.00-2.20 inches. There should be break in the precip this evening but some regeneration looks likely between 09-12z as another vort lobe moves into SE TX. Upper level winds remain diffluent but not quite as strongly as today. Fcst soundings look to be most saturated Thursday morning with some drying noted in the aftn with even some weak capping developing over the NW part of the area during the aftn. Will taper PoPs lower over the NW and higher toward the coast/southern half. On Friday, a weak cold front will inch its way toward the northern half of the region but probably stall just north of the area. The feature looks strong enough for showers and storms to develop especially over the northern half of the area Friday afternoon. Further south, fcst soundings show some drier air in the 850-700 mb layer and a weak cap near 800 mb. The weekend is showing some mixed signals as PW values remain 2.00 inches but convective temps warm into the lower 90s. Upper level winds not looking quite as diffluent so other than daytime heating and a weak sea breeze, not seeing a well defined trigger to increase PoPs. PW values perk back up next Monday with values once again exceeding 2.20 inches. Despite the higher PW air, fcst soundings show dry air in the 850-700 layer and also below 850 mb. A well defined upper level disturbance over North Texas will provide a glancing blow to the region but again, having trouble finding a trigger for widespread shra/tsra. Will maintain chance PoPs but confidence is low. Upper level ridging will try to expand into Texas from the east next Tues-Thu with a weak inverted upper trough sliding westward beneath the ridge. It looks like this feature will remain south of the HGX CWA but it could bring some isolated shra/tsra to the region as moisture levels briefly increase. 43 MARINE... Mainly light south winds (sometimes more variable and stronger in/around shower and thunderstorm activity) can be expected through the end of the week. A better onshore flow with south winds generally in a 10 to 15 knot range and increasing seas are anticipated over the weekend and into the start of next week under a slightly tighter pressure gradient. At this time, both winds a seas are expected to remain under caution levels. 42 && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 74 91 75 95 77 / 40 40 20 30 20 Houston (IAH) 75 90 78 94 77 / 30 50 20 40 20 Galveston (GLS) 79 87 82 89 82 / 40 60 40 40 30 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ Discussion...39
Area Forecast Discussion
National Weather Service Huntsville AL
908 PM CDT Wed Aug 2 2017 .NEAR TERM...(Tonight) Issued at 908 PM CDT Wed Aug 2 2017 Quiet weather prevailed across the greater Tennessee Valley this evening. Showers and storms that impacted parts of northwest Alabama in the mid afternoon have long since faded. The only activity within the 124 nmi range ring (where rain is measured) was occurring across portions of middle Tennessee, west of Nashville and mostly north of I-40. The infrared satellite view from GOES-16 indicated the higher altitude clouds moving in a SW-NE manner from northern Lousiana to the Carolinas and Virginia. Lower clouds with bases in the 10-12kft above ground level were scattered from the northwest Mississippi Delta, across northwest and north central Alabama, to western and middle Tennessee. Those clouds, and forecast soundings from the RAP and HRRR suggest they should thin somewhat during the overnight, maintaining partly cloudy skies. Deeper moisture present, and especially from the recent shower/thunderstorm activity, along with slightly longer nights that August offers, should be favorable for patchy fog formation. Given that NW Alabama had the most rainfall around the region (some mesonet sites recording over 1.5") those spots would be more likely to experience fog, along with areas near bodies of water and in sheltered spots. As such, have left this possibility in the forecast for the late night. The moisture should make for slightly warmer night time lows over NW AL - so made minor adjustments in this area. The rest of the forecast for the night time looks to be in fine shape at this time. .SHORT TERM...(Thursday through Friday) Issued at 249 PM CDT Wed Aug 2 2017 Not a whole lot of change in the short range models since yesterday. General trof position at 500 mb will remain over the southeast U.S. through Friday night. Minor waves will continue to track from the southern Plains into the Gulf South. A small wave is still progged to move east through AL and far southern TN on Thursday. Will maintain a low chance of showers/thunderstorms, with best chances still in our southeast counties in closer proximity to the higher vorticity in the wave. Cloud cover and temperatures will vary depending on precip development, but will stay the course with upper 80s to around 90 once again (warmest west including HSV and MSL). With the shortwave departing east and loss of solar heating, convection should die off quickly by around sunset. As a vigorous shortwave digs into the central Great Lakes on Friday, the trailing trof axis will move through the OH and TN valleys Friday and Friday evening. The associated cold front will slowly drop south through Friday evening. The highest chances of precipitation will be during the day Friday ahead of the front coinciding with peak heating. CAPE values of 1500-2500 j/kg and 30kt of 6km bulk shear will be sufficient for strong thunderstorms. However, activity will struggle to remain organized with weakening QG forcing and convergence along the front Friday evening. .LONG TERM...(Friday night through Tuesday) Issued at 249 PM CDT Wed Aug 2 2017 The front that will bring showers and thunderstorms on Friday will be to our south on Saturday but will slowly push back northward by Sunday. The southerly winds behind the front will pull back in plentiful moisture of dewpoints ~70 degrees and PWATS ~2 inches. An upper-level trough develops in the North Plains on Sunday and a series of disturbances in the base will lift up into the TN Valley Sunday and Monday. This will result in scattered to numerous showers and thunderstorms across the area capable of producing locally heavy rainfall. As the system progresses towards the Great Lakes, it will send a weak cold front to the area Monday night/Tues keeping a chance of storms through the extended forecast period. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 618 PM CDT Wed Aug 2 2017 VFR conditions are expected to prevail across N AL/S middle TN for the next 24 hours with a couple of exceptions: 1) reduced visibilities due to fog (3-5 SM), especially close to KMSL between 10Z-13Z, and 2) additional storm development that is possible late in the period. Any storms that develop may cause IFR-MVFR drops in VIS/CIGS mainly south of the TN River near K4A9, K8A0, KCMD, K4A6. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...NONE. TN...NONE. && $$ NEAR TERM...RSB SHORT TERM...17 LONG TERM...JMS AVIATION...SL.77 For more information please visit our website at
Area Forecast Discussion
National Weather Service Wilmington NC
947 PM EDT Wed Aug 2 2017 .SYNOPSIS... Moisture will slowly increase over the next few days, bolstered on Friday by the approach of a cold front. This front will weaken over the weekend to our west but ample moisture will linger for unsettled weather into early next week. Another cold front will approach the area from the northwest on Wednesday. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... As of 930 PM Wednesday...A slight update to the near term as now the NAM and HRRR are indicating that a disturbance rotating around the bottom of the large trough over the eastern U.S. will transport moisture into the region towards daybreak along the coast. I have upped the pops along the SC counties into Brunswick, New Hanover, Columbus and parts of Bladen and Pender as the moisture rides up the coast. The timing of the precipitation will begin along the southern portions of the cwa mainly an hour or two before sunrise to about an hour or two after sunrise as you move form south to north. The best chances of precipitation will be along the coastal areas and less chances farther north and inland. The the return of a light easterly flow have increased the low level moistures will moderate the low level temperatures are expected to fall into the upper 60s to the lower 70s. Highs on Thursday will be in the mid to upper 80s. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... As of 300 PM Wednesday...An area of tropical moisture in the GOM today will lift NE and drive at least a wave of low pressure up the coast Thursday night into Friday. This wave is forced to eject NE thanks to a deepening longwave trough dropping across the Southeast, and the question will be how close to the coast will this feature pass, and how much moisture will accompany it. ECM/NAM are much more robust with this feature bringing a closed surface reflection right along the coast with heavy rainfall, while the GFS is a bit weaker and drier. Current satellite imagery and presence of offshore stalled boundary suggest the wave will travel just east of the CWA, with highest POP across SE zones and into Cape Fear. Still some uncertainty into how much QPF will occur across the CWA, but with PWATs climbing above 2 inches Thursday night, WPC QPF seems reasonable with up to an inch far SE zones, and very little NW of i- 95. have tried to mimic this in the QPF forecast with LKLY POP east, SCHC west. This feature will lift NE away from the area Friday, but as the trough axis stays west of the coast, strung out vorticity, continued moist advection, and relatively lowered thicknesses will keep the potential for unsettled weather with showers and tstms through Friday night. Do not see any significant surface features during this time, and mid-level forcing is weak and strung out so while showers are possible all day Fri/Fri night, do not expect significant QPF or an all-day rainfall. Clouds and rainfall will keep highs below climo Friday, mid 80s near the coast and upr 80s well inland, with weak diurnal ranges producing mins only around 72-75 Friday night, a few degrees warmer than Thursday night. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... As of 3 PM Wednesday...The area will remain between a west Atlantic ridge and a Great Lakes trough through the period. Separate cold fronts will drop into the area over the weekend and again on Wednesday. The net result will be an unsettled period with a chance of showers and thunderstorms each day though the greatest likelihood for rain should be the weekend and again Wednesday. Temperatures through the period will generally run in the mid to upper 80s by day and drop to the lower to middle 70s overnight. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... As of 23Z...VFR conditions to continue across the terminals through 06 utc when BR formation is possible. previous discussion cited guidance hinting IFR is likely at KFLO and MVFR at all other sites. Left br in tafs except for KCRE as south to se wind should mix it a bit to keep br from developing. Winds will be generally less than 8 knots becoming east to south along the coast and lighter at inland taf locations. Chances for precipiation and increase in clouds begin to appear shortly after daybreaks on NAM and Euro models mainly along the coast decided to included vcts at coastal terminals. Better chance of pcpn moving across the terminals after 21z as models develop low across the SE and move it across the region by evening. NAM is the wettest model with GFS and Euro less either way looks like the chance of pcpn increases late day. Extended Outlook...Possible periods of MVFR/IFR Thursday night through Sunday as chances of showers and thunderstorms increase at area TAF sites. && .MARINE... NEAR TERM /THROUGH THURSDAY/... As of 930 PM Wednesday...with that area of weak low pressure moving up the coast overnight into Thursday winds will become southeast 10 to 15 knots. showers and thunderstorms chances increase during the day on Thursday starting around sunrise across the SC waters slowly progressing to just after sunrise in the NC coastal waters. Seas will run 2 to 3 feet with a slight increase to 4 ft by late Thursday. SHORT TERM MARINE/THURSDAY NIGHT THROUGH FRIDAY NIGHT/ As of 300 PM Wednesday...High pressure offshore will expand through late week ahead of a cold front approaching very slowly from the NW. This front will not reach the area this period, and instead function to tighten the gradient across the waters driving SW winds up from 10-15 kts Thursday night, to 15-20 kts Friday night. A 2ft/9sec SE swell will exist through the period, but become increasingly masked by an amplifying 5-6sec SW wind wave which will grow towards 5 ft late. This will create significant seas of at least 3-4 ft late Friday, with some 5 fters possible, up from 2-3 ft Thursday night. LONG TERM /SATURDAY THROUGH MONDAY/... As of 3 PM Wednesday...Expect southwest winds 10 to 15 KT Saturday to weaken slightly to about 10 KT Saturday night and continue through Sunday night before increasing to 10 to 15 KT again Monday. Seas should run 2 to 3 FT though a few 4 footers are possible Saturday. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ SYNOPSIS...RAN NEAR TERM...MAC SHORT TERM...RAN LONG TERM...MBB AVIATION...MAC MARINE...MAC/RAN
Area Forecast Discussion
National Weather Service Wilmington OH
953 PM EDT Wed Aug 2 2017 .SYNOPSIS... Showers and thunderstorms will continue to weaken this evening as the sunsets with showers and thunderstorms expected again Thursday. More storms can be expected as a cold front moves through the area on Friday. High pressure will build in for the weekend. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... During the day Thursday a closed low pressure will be located over Minnesota and be slowly pushing southeast. Ahead of the closed low a jet streak will extend across Illinois into Michigan. This puts the favorable position for shower and thunderstorm coverage more towards Indiana now. Latest HRRR runs also tends to indicate better coverage out west. Still though, both NAM and GFS forecast soundings both destabilize tomorrow afternoon with mean flow very weak. This again supports scattered thunderstorm coverage in the afternoon. Prev Discussion-> Scattered storms will continue through the late afternoon and diminish with the loss of heating early this evening. Locally heavy rainfall and gusty winds with minor downbursts will remain possible. Beyond early evening, expect little to no activity with partly cloudy skies. Lows will be a bit warmer than last night. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... Weak troughing will persist across the region with minor disturbances moving through it. This will result in additional scattered showers and thunderstorms, primarily in the afternoon. However, there is the possibility of some activity lingering into the night in the northwest counties. Weak wind fields will result in unorganized storms with locally heavy rainfall and gusty winds the primary concern. Highs should be close to persistence. Lows will be in the mid to upper 60s. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... A fairly strong mid level short wave embedded in a broader upper level trough will pivot east across the southern Great Lakes Friday into Friday night. This will help drive an associated cold front east across the upper Ohio Valley through the day on Friday. The last couple of model runs have trended somewhat slower with the frontal passage and as as a result, our area will be in a somewhat more favorable position for thunderstorm development. As we destabilize ahead of the front through late morning and into the early afternoon, expect to see an increase in coverage along and ahead of the front across our area. Precipitation should then taper off fairly quickly from west to east through the mid to late afternoon hours as the front moves east. Mid and deep layer shear will be on the increase along and ahead of the front as wind fields increase ahead of the short wave. This will combine with the slower timing of the front to increase our severe threat, particularly across our eastern areas where the better instabilities should exist through mid afternoon. High pressure and a cooler, drier airmass will build in behind the front for the weekend. Highs on Saturday and Sunday will mainly be in the mid to upper 70s with morning lows in the mid to upper 50s. The 12Z GFS has trended faster with the approach of the next trough axis early next week but it is still slower than the past several runs of the ECMWF. As a result, will speed up pcpn chances heading into Sunday night and then linger a chance through the day on Monday. With the faster timing, will also go ahead and dry us out Tuesday into Wednesday. High temperatures will remain in the mid to upper 70s through mid week. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... Scattered convection continues this evening and should decrease in activity over the next couple of hours as the sunsets. Overnight weak southwest flow will continue with some VFR clouds. High res models do show a weak signal of some patchy ground fog, but think chance is limited mainly to the river valleys. Thursday morning cumulus will quickly develop as moisture remains abundant across the area. During the afternoon scattered showers and thunderstorms will again be possible as forecast soundings quickly destabilize (both GFS and NAM). Coverage on high res models looks slightly better west towards the upper level support. For now have just added a vicinity thunder into the TAFs as the atmosphere again looks to destabilize. OUTLOOK...Thunderstorms are possible Thursday evening through Friday. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ SYNOPSIS...Haines NEAR TERM...Haines SHORT TERM... LONG TERM...JGL AVIATION...Haines
Area Forecast Discussion
National Weather Service Jacksonville FL
935 PM EDT Wed Aug 2 2017 ...PERIODS OF HEAVY RAINFALL ACROSS NORTHEAST FLORIDA TONIGHT AND SOUTHEAST GEORGIA ON THURSDAY... .UPDATE...Deep layer moisture over the area combined with shortwave trough over northeast FL and far southeast GA, and a weak frontal boundary over northeast FL continues to produce showers and a few embedded thunderstorms. With loss of heating, all convective activity is trending to a weak phase this evening. However...activity over the northeast Gulf of Mexico will be activity overnight due to abundant moisture and low level moisture flux convergence. This activity should keep the Suwannee Valley area, including Gilchrist, Alachua and western Marion county as well in a flux of on and off showers and a few storms. Locally heavy rainfall is the main concern here. Have updated the forecast to reflect current trends and leaned toward latest HRRR runs for POP forecast. Min temps tonight in the lower to mid 70s. Thursday...deep southwest flow with very moisture environment with PWATs of 2 to 2.4 inches and mid to upper level troughing over the southeast states will produce scattered to numerous showers and storms. Periods of heavy rainfall expected. Highs may be held in the mid 80s...possibly some upper 80s over far southeast zones. Flooding/flash flooding remains the primary concern this period, and excessive rainfall will continue on Thursday. Widespread totals of 1 to 2 inches are expected, with localized areas receiving much higher amounts in training showers and thunderstorms. && .AVIATION...VFR at this time with multilayered clouds overnight but chance of MVFR cigs later on tonight. Showers and a few storms expected to decrease in chance overnight except for GNV. Have continued TEMPO group for GNV tonight. Any lower CIGS down to IFR seemed to be most probable away from terminals over inland SE GA and perhaps over parts of the Suwanee Valley. High rain chances for Thursday with showers and thunderstorms expected with MVFR and IFR restrictions expected at times. && .MARINE...No major changes tonight with southeast winds over the GA zones near the front and south winds over NE FL waters. Winds should turn south over all waters by early morning. Winds about 10-15 kt. Seas mainly 2-3 ft outside of thunderstorms. && .PRELIMINARY POINT TEMPS/POPS... AMG 73 86 73 86 / 20 80 40 60 SSI 76 85 76 86 / 80 70 30 40 JAX 74 86 75 89 / 60 60 10 30 SGJ 74 87 74 89 / 30 50 20 40 GNV 72 85 72 90 / 60 70 10 40 OCF 74 87 73 91 / 50 50 10 40 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. && $$ Shashy/Zibura/Corless
Area Forecast Discussion...UPDATED
National Weather Service Twin Cities/Chanhassen MN
938 PM CDT Wed Aug 2 2017 .UPDATE... Issued at 938 PM CDT Wed Aug 2 2017 The forecast for late tonight through Thursday remains largely on track. One important trend to keep an eye on is a southward trend in the CAMs and now even the NAM with the surface cyclone across far southern MN closer to the ECMWF. This could focus the deformation band of heavy rain further south as well. Latest RAP and HRRR are more widespread with the 1+ inch totals and have several pockets of 2-3+ inch totals across the southern half of MN through mid afternoon. This is in stark difference to that of the GFS and 12Z runs of the NMM/ARW which kept most of southern MN dry from mid morning onward following brief a line of storms with the cold front. This evolution will ultimately depend on the interaction with the upper low now dropping south into north central North Dakota, clearly evident on water vapor imagery. && .SHORT TERM...(This evening through Thursday) Issued at 420 PM CDT Wed Aug 2 2017 Weather in the short term will be dominated by an anomalously strong storm system, bringing with it a chilly & damp Thursday that will feel more like October than early August. A potent shortwave continues to dig over the Dakotas with a widespread shield of precipitation continuing to move off to the east. This precipitation is only expected to become more widespread into the evening as a surface low deepens over SE SD. Models this afternoon have come into general agreement with bringing the low a little further south, tracking generally along I-90. Not often you get to talk about deformation bands in early-August but expecting the heaviest precipitation to fall along the axis of greatest deformation, more typical of something we`d see with a winter storm. The track of the low along I-90 places this axis along a Fargo-Brainerd-Hayward WI line where a widespread 1.5-2" of rainfall is expected. Flooding is not anticipated to be an issue with this system as we`re expecting a steady rain falling over a long enough time frame where basins should have no problem handling this extra water. Rainfall is expected to begin around 10pm this evening across far-western MN, and continue to spread east across the state, reaching the Twin Cities around 3am & eventually into west-central WI towards sunrise. As noted earlier the band of heaviest rainfall will set fall over central MN but the rest of southern MN & west-central MN can still expect close to 1" of rain. In addition to the steady gray rainfall, Thursday will feel even more raw with temperatures close to 20 degrees below normal. The forecast high of 64 at MSP is more typical for October 1st or 2nd! Highs will likely come just after midnight & struggle to warm during the day with the consistent rain & cloud cover. Areas in central Minnesota under the main axis of precipitation will even struggle to make it out of the 50s. Precipitation will taper off Thursday evening from west to east across the area & should be off into central Wisconsin by sunrise Friday. Clearing skies & northerly winds behind this system will bring another fall-like, but much more pleasant, day for Friday. .LONG TERM...(Thursday night through Wednesday) Issued at 420 PM CDT Wed Aug 2 2017 The dominate theme for the long term will be northwest flow and a prolonged period of below normal temperatures. Our best chances for rain look to be primarily diurnally driven showers this weekend and then tied to a frontal passage Tuesday night/Wednesday next week. We should start the long term off fairly benign as high pressure slides across the area in the wake of Thursday`s system. We`ll have skies clearing from west to east with light winds. H85 temps of 10- 12C though will ensure highs are 5-10 degrees below normal. For the weekend, we get stuck in a wavy northwest flow, with cool temepratures aloft promoting steep afternoon lapse rates and the threat for showers. Think the GFS is way overdone with the strong system and washout it brings to the area Sunday, so stayed closer to a ECMWF/Canadian blend for the weekend. We did knock back precip chances quite a bit for Saturday, with the likelies in western MN now down to chance pops as the ECMWF and Canadian show the shortwave driving precip from central SoDak Friday night down into Iowa Saturday afternoon. For the MPX area it`s diurnal instability driven showers that will be our threat, though the ECMWF shows the greatest instability axis existing from northern WI back through northeast MN, so we may not see all that much activity locally. Sunday looks to be more of the same as we stay in a pocket of relatively cool air aloft. Again ignoring the 12z GFS (which has a washout similar to what we are expecting Thursday), we expect scattered afternoon activity, though no severe weather is expected. We finally get rising heights on Monday, which will push the cold pool aloft off to our east, ending the threat for diurnal showers. However, there will be another strong shortwave dropping through south through central Canada. This wave will drive a seasonably strong cold front across the area Tuesday night/Wednesday. This will offer us our warmest day of the long term and only opportunity for warming into the 80s in the southwest low level flow ahead of the front Tuesday. Behind the front, h85 temps drop down to around 8C, so we`ll be struggling to get much past 70 at the end of next week, even with full sunshine. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 725 PM CDT Wed Aug 2 2017 Conditions will deteriorate from west to east tonight into Thursday. Rain will gradually build eastward overnight, with the heaviest rain likely across central/eastern MN into western WI, or roughly along and north of I-94 late tonight and Thursday. Widespread MVFR cigs expected by morning, but some IFR cigs are also expected across western WI Thursday. Winds will become north and gust as high as 25-30 kt behind the low Thursday afternoon. KMSP...MVFR cigs and -shra will arrive after 09Z, with heaviest rain expected Thursday morning and cigs approaching IFR levels. /OUTLOOK FOR KMSP/ Fri...VFR. Wind NW 5-10 kts. Sat...VFR. Chc MVFR/-SHRA late. Wind light/variable. Sun...VFR. Chc MVFR/-SHRA. Wind NE 5 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. && $$ UPDATE...BORGHOFF SHORT TERM...ETA LONG TERM...MPG AVIATION...BORGHOFF
Area Forecast Discussion
National Weather Service Omaha/Valley NE
721 PM CDT Wed Aug 2 2017 .SHORT TERM...(Tonight through Saturday) Issued at 255 PM CDT Wed Aug 2 2017 The primary forecast issues in the short term and precipitation chances from tonight into Thursday morning, and then also again from late Friday night into Saturday. Taking a look at the current situation. A cold front extended from a low pressure center that was just east of Phillip, SD at 2 pm. The atmosphere over eastern NE has destabilized, with MLCAPE values mainly 1000 to 2500 J/kg. Sfc to 6 km bulk shear is not impressive, generally 30 kts or less. There is an axis of higher downdraft CAPE though, upwards to 1000 or so centered along highway 81. The highest risk of severe storms is to our west, but there does appear to be some risk of gusty winds and maybe some hail in parts of our area until 9 pm or so. That would be mainly northwest of a line from about Pender to Seward. Did give the convection allowing models (CAMs) a bit more weight for this evening - compared to the parameterized models which are slower to bring storms into our area. Tended to favor a blend of the 12Z NAM, 15Z SREF, the 12Z ECMWF and recent RAP runs for later tonight. The RAP however seemed too wet and thus did give its QPF much weight. That surface low and a cold front will continue to move east through the region during the overnight hours, but the strongest QG forcing remains to our north. So that is probably where the heaviest QPF will be. Additional showers and storms, at least scattered coverage, should develop with the frontal circulation overnight. Precipitation will likely move out of southeast NE and southwest IA by late Thursday morning, but it seems possible that some instability showers may develop in the afternoon. That would mainly be across the northern half of the forecast area. Coverage seems like it would be very isolated, so will not include in official forecast at this point. Highs will be cooler than today, in the 70s. Cool high pressure will build over the area Thursday night, with lows expected to be mostly from 48 to 52. The high moves east on Friday and return flow starts to strengthen. Temperatures will start out cool though and mostly reach 75 to 80 in the afternoon. Will keep chance POPs going in our western counties for late Friday night and then chances mainly 30 to 60 percent Saturday. .LONG TERM...(Saturday night through Wednesday) Issued at 255 PM CDT Wed Aug 2 2017 Timing the ending of precipitation chances ending is not clear for the rest of the weekend, so will keep some chance of showers and storms into Sunday. A pretty cool airmass will likely get pulled down into the area Sunday night and Monday but fairly deep mixing with northwest winds in the afternoon should offset the cooling. Temperatures then moderate a little toward the mid part of next week but only to the lower 80s, still a bit below normal. More rain chances return for Tuesday night and Wednesday. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 644 PM CDT Wed Aug 2 2017 A couple of rounds of showers and thunderstorms will push through the area tonight initially through northeast Nebraska then spreading southeast through 11Z. Due to the spotty nature of the thunderstorms will include showers/vcts. Behind the cold front surface winds strengthen out of the northwest to 15 to 25kts after 11Z. Some MVFR cigs may move into northeast Nebraska Thursday morning for a few hours. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ SHORT TERM...Miller LONG TERM...Miller AVIATION...Zapotocny
Area Forecast Discussion
National Weather Service Nashville TN
726 PM CDT Wed Aug 2 2017 .UPDATE... FOR EVENING DISCUSSION. && .DISCUSSION... Upper divergence appears to be quite weak overnight. The upper shortwave energy will be strongest way upstream as well as across portions of the deep south. Hrrr indicates that the ongoing convection should die out by 04z-05z. However, will opt to increase the pops into the chc category for this evening across northwestern areas, prior. Otw, will add some patchy across the area for late tonight. Current dewpoint depressions are rather low and numerical guidance does support lower vsbys, especially for the southeast half. Furthermore, partial clearing is expected overnight. Min temps still look to be on track as fcst mins are close to current dewpoints. Update out shortly. && .AVIATION... 00Z TAF DISCUSSION. CKV/BNA/MQY/CSV...Other than light shwrs CSV that may persist until 03/02Z, convection potential ended terminals this evening. Some MVFR fog possible terminals 03/08Z-03/14Z. Otherwise per above mentioned sfc/upper level pattern, iso/sct shwrs/tstms once again possible 03/17Z-03/24Z per moist/unstable atm continuance. Can not precisely forecast terminal timing/impacts shwrs/tstms during this period, but certainly potential development/moving into vcnty possible. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION......21 AVIATION........31
Area Forecast Discussion
National Weather Service New York NY
951 PM EDT Wed Aug 2 2017 .SYNOPSIS... High pressure will remain over the Western Atlantic through Thursday, stretching into the Northeast. Low pressure then moves through the Great Lakes Region on Friday and sends a cold front through the local area on Saturday as it is passes to our north. High pressure then builds in on Sunday, followed by another low pressure system early next week. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... Showers and thunderstorms have ended across the entire CWA, so lowered POPs to reflect current observations. The only thing that needs to be watched is the line of showers and thunderstorms over central Pennsylvania. It is currently weakening, but the HRRR model does show some precipitation from this feature moving into western portions by 2 am and thereafter, continuing to weaken as it moves through. However, there is very little surface instability to work with, so kept precipitation out of the area overnight. Otherwise, made updated forecast to reflect current observations. Convection will continue into early evening before weakening after sunset with loss of heating and with best shortwave forcing passing to the NE. The threat of at least minor urban/small stream flooding remains with the slow motion of the storm cells. Localized flash flooding cannot be ruled out either. Otherwise, remaining mostly cloudy for the overnight with sufficient moisture aloft. Patchy fog is also expected away from the NYC metro. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... Broad upper troughing continues on Thursday with a weak surface trough probably developing nearby during the afternoon, but there does not appear to be any well defined shortwaves. So the surface trough plus any weak shortwave, seabreeze or outflow boundary will act as the focus for convection. Will cap PoPs in the chance category with a focus in the afternoon as convection will be mainly diurnally driven. The steering flow remains weak, so locally heavy rainfall is possible as any storm would be slow-moving. Near seasonable high temperatures are forecast on Thursday. The flow aloft becomes more anticyclonic Thursday night. This combined and with the loss of daytime heating would serve to lessen the coverage of showers/storms, however both NAM and GFS seem to indicate weak shortwave and isentropic lift shifting through during the night, so will go with some form of PoPs for most areas through the night. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... The region then remains under SW flow aloft Friday-Friday night, and with no notable shortwave progged through the area, would expect mainly pulse diurnally driven convection, mainly over the interior into Friday evening, as onshore flow will enable local marine influence to serve as a limiting factor for coastal zones. An approaching cold front could trigger some showers/storms late Friday night over far western zones, so have slight chance pops to reflect this. The axis of a closed upper low over SE Canada moves into the region on Saturday, this should trigger some scattered showers and thunderstorms with its passage. With CAPEs forecast to be around 1000-2000 J/kg (mainly over W 1/2 of CWA) and the region being in the right rear quadrant of an 85+ kt 300 hPa jet, there is some potential for some strong to possibly severe storms, mainly across NE NJ/Lower Hudson Valley/SW CT and possibly into remainder of the NYC metro. The trough axis lifts to the NE Saturday night, but other than maybe some lingering convection over SE CT early, it should be dry. SW flow aloft Sunday and Sunday night with no shortwaves of note embedded in the flow should allow for both periods to be dry, with not to much in the way of cloud cover. Models then differ on handling of a northern stream shortwave trough early next week. The ECMWF is more progressive, while the GFS/CMC are slower and a bit stronger. The net result should be the same, with a low riding along a frontal boundary stalled to our south. The main issue is timing of precipitation, and amount. Both models have been consistent in their solutions, so have gone with a compromise between the two camps given the inherent uncertainty this far out. For now, limit chance pops to W zones Monday afternoon, then have everywhere Monday night. For now only have slight chance pops on Tuesday, but if slower solutions are right, could be a rainy Tuesday as well. High pressure otherwise builds in for Wednesday with dry weather. Temperatures should be near normal Thursday night-Saturday, then below normal Saturday night-Sunday. Lows Sunday night and Monday night should be near normal and highs Monday-Tuesday below normal. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... VFR now that tstms have ended. May have to watch KSWF for a brief round of additional showers after midnight, otherwise will then have to watch from about 08Z-13Z mainly there and out east at KGON for development of IFR conditions. KEWR/KTEB and also KISP/KBDR/KHPN could briefly be on the edge of some of these lower conditions. Light/variable flow should settle in on a S-SE direction overnight, followed by coastal sea breeze development in similar fashion to previous days. Scattered afternoon tstms are possible mainly NW of the NYC metros in the afternoon, with overall coverage/impact likely to be less than that of today. ...NY Metro Enhanced Aviation Weather Support... Detailed information, including hourly TAF wind component fcsts, can be found at: http:/ KJFK TAF Comments: No unscheduled AMD expected. KLGA TAF Comments: No unscheduled AMD expected. KEWR TAF Comments: AMD possible for lower flight cat overnight into early Thu morning. KTEB TAF Comments: AMD possible for lower flight cat overnight into early Thu morning. KHPN TAF Comments: No AMD scheduled. KISP TAF Comments: AMD possible for lower flight cat overnight into early Thu morning. .OUTLOOK FOR 00Z FRIDAY THROUGH MONDAY... .THURSDAY NIGHT...Areas of mainly MVFR fog/haze late at the outlying terminals. .FRIDAY...Isolated afternoon TSRA inland. S-SW wind 10-15 kt. G20KT possible late day along the coast. .SATURDAY...Scattered tstms possible. .SUNDAY...VFR. .MON...Becoming MVFR-IFR with increasing chances of rain. SE winds 15-20 kt. && .MARINE... A relaxed pressure gradient over the region through Monday will limit winds to around 10 kt or less, except up to 15 kt in seabreezes in the NY Bight area Thursday and Friday afternoons. Given these relatively light winds and no significant swell, seas/waves will remain well below small-craft levels through Monday as a result. && .HYDROLOGY... Locally heavy rainfall is possible with any stronger convection through Saturday, with nuisance flooding of urban/poor drainage areas the main threat. There is at least a low chance of localized flash flooding into this evening. Otherwise, no significant hydrologic impacts are expected through at least Monday morning. There is some potential for widespread rainfall from Monday possibly into Tuesday. At this time, it is to early to specify any amounts or impacts during this time frame. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JC NEAR TERM...JC/JP SHORT TERM...JC LONG TERM...Maloit AVIATION...Goodman MARINE...JC/Maloit HYDROLOGY...JC/Maloit
Area Forecast Discussion
National Weather Service Pueblo CO
345 PM MDT Wed Aug 2 2017 .SHORT TERM...(This evening through Thursday) Issued at 344 PM MDT Wed Aug 2 2017 Upper wave rotating around the ridge and over CO this afternoon with line of rather fast moving tsra dropping south across the region. Mesoscale models, including the HRRR, looking a little underdone with CAPE, as SPC and LAPS mesoanalysis suggest values well over 1000 J/KG over much of the eastern plains, which is a few hundred J/KG more most models. As a result, convection has started slightly earlier and is a little more vigorous than model forecasts, especially over the eastern mountains and I-25 corridor. For the rest of the afternoon and evening, expect isolated to scattered tsra over much of the area, with eastern mountains and far eastern plains favored for best convective coverage. Given rather large instability (CAPE 2000 J/KG) over the far ern plains, some concern for strong convection building south along the KS border this evening, with HRRR hinting at this scenario as well. Convection over the mountains will begin to diminish by late evening, but may linger much of the night on the plains, as pre-frontal trough drops through by midnight, followed by the main cold front around sunrise. On Thu, cold front exits the area to the south by mid to late morning, with models suggesting at least a few -shra on the plains along and behind the boundary through midday. By afternoon, mountains destabilize with rather widespread convection developing, especially along and west of I-25 where upslope flow aides in development. There will be a threat for a few stronger storms over the srn Sangres/srn I-25 corridor and along the NM border given 30- 40 kt 0-6km shear, along with the potential for heavy rain over eastern mountain burn scars. Would expect least coverage of storms over the eastern plains/lower Ark Valley, as air mass may be too cool/stable for much in the way of convection. Max temps behind the front over the eastern mountains and plains will run 10-15f cooler than Wed maxes, with more modest cooling of 2-4f farther west over the remaining mountains and interior valleys. .LONG TERM...(Thursday night through Wednesday) Issued at 344 PM MDT Wed Aug 2 2017 The general synoptic scale pattern over the majority of the extended forecast period includes shortwave troughs propagating over the region and an upper level ridge consistently over northern Mexico. The NW flow will limit the amount of monsoonal moisture available, but thunderstorms will still be possible with the shortwaves developing over the region. Thursday evening will consist of showers and thunderstorms overnight with post frontal winds conducive to upslope flow over the Raton Mesa and the Palmer Divide in unison with CAPE values ranging from 1200 - 1500 J/kg. During the overnight hours, the energy in the atmosphere diminishes, cutting off thunderstorms. Friday will have a chance for thunderstorms, but a well capped atmosphere will limit initiation towards the latter parts of the day. The storms that do develop will initiate strongly, but timeliness of development and lack of strong shear, will limit the storm`s life cycle. The next cold front will propagate over the region during late morning hours on Saturday and stall through the afternoon and evening hours. The post frontal winds will be conducive for upslope flow, enabling showers and thunderstorms during the overnight hours. Sunday and Monday will be cooler, post cold front, but upslope flow is still conducive for thunderstorms, particularly over the SE mountains. The next cold front and it`s associated shortwave trough will begin to develop over the region Tuesday into Wednesday, with showers and thunderstorms possible during the afternoon and evening hours. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 344 PM MDT Wed Aug 2 2017 Will carry a VCTS mention at all terminals into the evening , and some MVFR conditions may be possible under some of the stronger storms. Cold front will drop south through KCOS and KPUB after 06z, leading to a period of gusty N-NE winds some isolated -shra until mid-morning Thu. May also see some areas of MVFR cigs develop after 10z on the eastern plains, possibly impacting KCOS and KPUB through the morning. Tsra will become widespread over the mountains Thu afternoon, with storms possible at all taf sites after about 20z. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...PETERSEN LONG TERM...SKELLY AVIATION...PETERSEN
Area Forecast Discussion
National Weather Service Blacksburg VA
952 PM EDT Wed Aug 2 2017 .SYNOPSIS... Weak high pressure resides across the region into Thursday. A cold front approaches Friday, moving across Saturday before stalling across the Carolinas over the weekend. The front then lifts back north by early next week ahead of another cold front arriving from the west. && .NEAR TERM /THROUGH THURSDAY/... As of 945 PM EDT Wednesday... Precip still remains clear of the forecast area. Some showers to the west are struggling to make it across the mountains and are not expected to impact the forecast area. Still an area of clearing skies making its way into the piedmont now, however model guidance does suggest that clouds to the west will manage to make for at least partly cloudy skies over the course of the evening. Due to this area of clearing, temperatures are dropping a bit faster than originally forecast through the mountains, therefore adjusted the overnight lows slightly down through those elevations. Whether or not this comes to fruition will be a fight against higher than expected dew points. As it stands, no significant changes have been noted to any overnight fog forecast earlier. As of 730 PM EDT Wednesday... Current radar shows that precipitation has ended for now in and around the forecast area. Current HRRR guidance does indicate a small chance that some light showers may be possible in parts of the piedmont and Southeast WV the next couple of hours. However that seems unlikely now that we are nearing sunset and storms and showers to the west are beginning to dissipate. PoPs have been adjusted accordingly. METSAT indicates that there is some clearing moving in from the west therefore sky conditions have been adjusted accordingly. As of 300 PM EDT Wednesday... Forcing for this afternoons current storms has been weak but relying on differential heating and some low level convergence. Models still have hard time with placement, but still advertise better coverage later this afternoon across our NC mountains in association with shortwave moving across northeast GA into central NC. Persistent high clouds has kept instability limited with MLCAPEs under 500 J/KG, but DCAPES are running close to a 1000 J/KG. Will have to watch for any isolated storms to pulse to strong to severe levels with a downburst the main threat. Still threat is very low, so no mention in the HWO. Will see activity across the mountains into the foothills in a widely scattered to isolated fashion fade by mid evening. Skies overnight should clear some, but a few models are hinting at more high clouds streaming across the southern CWA after midnight. Will limit fog to the valleys for now. Lows close to normal with upper 50s to lower 60s mountains, to mid to upper 60s across the piedmont to Roanoke. Thursday upper pattern unchanged with axis of 5h trough across the TN valley and southwest flow aloft. Sfc pattern stays the same as well, and models advertise again a shotgun pattern for showers/storms during the afternoon, mainly over the ridges and adjacent areas. Looks like better deep convection associated with low off the coast of NC will become widespread along the NC coast. Could see a minimal amount of showers/storms if we get more into the subsidence zone with this system. High temperatures running from the upper 70s to mid 80s over the mountains, valleys, to mid 80s to around 90 east including Roanoke. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/... As of 400 PM EDT Wednesday... Northern stream trough will amplify enough on Friday to push a cold front through the area late Friday or Friday night. While there are still some questions on exact timing, trend will be greater shower and thunderstorm coverage. For the weekend, the front is forecast to sag just south of the forecast area before stalling across the Carolinas... suggesting a 24-36 hour period of drying before the front returns north as a warm front the first part of next week. Warm temperatures and pooling of dewpoints ahead of the front Friday will support scattered to numerous afternoon and evening thunderstorms, with marginal risk for severe. Somewhat cooler temperatures are expected behind the front Saturday. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... As of 400 PM EDT Wednesday... A strong northern stream shortwave trough is forecast to move east through the Northern Plains and southern Canadian Border Sunday, amplifying as it moves into the Great Lakes Monday. This pattern suggests old frontal boundary to our south will move north as a warm front as the wind flow backs ahead of the approaching upper level trough...the return of warm moist flow resulting in a renewed daily threat of showers and thunderstorms for the first half of next week. Temperatures look to be pretty close to normal...maybe a degree or two under normal if we end up with more cloud cover due to proximity of the front. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... As of 800 PM EDT Wednesday... Main issue during the forecast period will be the onset of fog for locations in the valleys overnight, particularly at LWB where LIFR conditions appear the most likely. IFR conditions should also set in at BCB for a couple of hours before sunrise. Some light fog is also possible at LYH as they will fall to the crossover temperature tonight. Otherwise, VFR conditions and light to calm winds due to high pressure are expected for the forecast period. Tomorrow afternoon may again feature terrain induced showers and thunderstorms. However due to little to no larger forcing mechanisms they look to be rather isolated in nature at this point. Extended Aviation Discussion... Mostly VFR conditions are expected to continue through late in the week as a large area of high pressure lingers across the region, while gradually weakening. Some late night/early morning fog will be possible in the mountain and river valleys each morning. Next chance of reduced visibilities in isolated convection may occur Thursday afternoon over the mountains. A cold front will move into the area late Friday into Saturday with perhaps a round of sub- VFR ceilings and visibilities in showers and thunderstorms espcly Friday evening. Front stalls just south of the area by Sunday with possible clouds/showers and sub- VFR conditions returning north into southern sections by late in the day. && .EQUIPMENT... As of 1040 AM EDT Tuesday... The radar will be down most of the time through Wednesday due to an upgrade on the signal processor. If the upgrade goes well, the radar may be intermittently available Thursday and back to continuous operation Friday. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...JH/WP NEAR TERM...JR/WP SHORT TERM...PM LONG TERM...PM AVIATION...JR/WP EQUIPMENT...WP
Area Forecast Discussion
National Weather Service Shreveport LA
1024 PM CDT Wed Aug 2 2017 .UPDATE... Lowered pops and kept E TX and LA southern tier of parishes. && .DISCUSSION... Lots of stars in place this evening with lower to mid 70s, more like September than July. We have lowered pops to pretty much where the showers are decaying in place. Our VAD is showing shallow SE flow to 2kft and wind quickly backs to E/NE up to 10kft. 00Z Nam and HRRR agree for a quiet night. /24/ && .PREV DISCUSSION... /issued 630 PM CDT Wed Aug 2 2017/ AVIATION... For the 03/00Z terminals...VFR ceilings this evening will gradually degrade to MVFR/IFR. Could see brief LIFR conditions across some terminals around daybreak. Conditions to gradually improve to VFR by 03/18Z with VCTS conditions possible around LFK thereafter. Otherwise, light and variable winds tonight to become east at around 5 knots on Thursday. /05/ PREV DISCUSSION... /issued 401 PM CDT Wed Aug 2 2017/ DISCUSSION... Widespread area of rain continues to move east-southeast across much of East Texas and portions of Louisiana south of Interstate 20. Farther north, more isolated convection has been developing in the very moist and unstable environment. Convective coverage should gradually diminish later this evening, but an upper trough slowly moving through the region will continue to provide a source for vertical ascent and more convective development. A old frontal boundary near the Gulf coast should keep most of the showers and thunderstorms south of Interstate 20 tonight. The overall synoptic setup for Thursday should be fairly similar to today. The coverage of precipitation should be somewhat lower on Thursday, however. On Friday, an upper trough moving across the Upper Midwest and across the Great Lakes will push a cold front across the area. This front will provide an additional focus for convection across the entire area on Friday. During the weekend, the front will move back north as a warm front while yet another shortwave trough pass over the Southern Plains. This will lead to more showers and thunderstorms during the weekend. Unsettled weather will continue into early next week as another potent shortwave trough moves across the Midwest and another surface cold front moves southeast into the region. Rain chances appear to be a fixture in the forecast through at least Tuesday. The atmosphere will remain quite moist and unstable for the next several days. Precipitable water values are progged to be between 1.75 and 2.00 inches through at least Saturday night. This suggests that convection may continue to be efficient rain producers. I would not be surprised to see my forecast rainfall amounts be underestimated for many locations over the next several days. Unfortunately, in this type of pattern, forecasting where the bands of heaviest rain occurs is very difficult as the biggest factors are typically driven by mesoscale and micro scale processes, and where mesoscale boundaries become established each day. This remains a highly anomalous pattern for this time of year. && .PRELIMINARY POINT TEMPS/POPS... SHV 71 89 73 92 / 20 30 20 40 MLU 70 90 72 91 / 20 30 20 50 DEQ 67 88 69 87 / 20 20 20 40 TXK 69 88 71 89 / 20 20 20 40 ELD 68 89 71 90 / 20 20 20 40 TYR 70 87 73 91 / 30 20 20 40 GGG 70 88 72 91 / 20 30 20 40 LFK 71 89 73 92 / 40 40 20 40 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...None. TX...None. && $$ 24/05/09
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