Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/12/17

Area Forecast Discussion
National Weather Service Albany NY
1045 PM EDT Tue Apr 11 2017 .SYNOPSIS... A cold front will cross the region overnight, bringing a chance of showers. Drier and much cooler weather will return for tomorrow afternoon into Thursday with high pressure building into the region. Fair weather is forecast for Friday after a chilly start to the day. && .NEAR TERM /THROUGH WEDNESDAY/... As of 1045 PM EDT...A prefrontal sfc trough moved through most of the region, as the cold front continues to slowly move south/southeast from western and northern NY, as well as north- central VT. The shower activity has diminished over the region based on the KENX radar. However, a weak wave and mid-level short-wave is approaching from w-cntrl PA. This will increase the shower coverage once again along the front, and we increased the pops after midnight, especially between 1 and 3 am based on the latest HRRR and NAM12. There is little or no instability so the slight chc pops for thunderstorms were removed from the forecast. Temps were retooled based on the hourly trends, as temps are in the lower to mid 40s over the southern Adirondacks and southern Greens and 50s to lower 60s, except over the mid- Hudson Valley and NW CT, where some mid and upper 60s continues. Lows tonight will be in the 40s to upper 50s. Lingering isolated to scattered showers are expected in eastern NY Wednesday morning and lasting into early afternoon in western New England. Some clearing is possible by mid to late afternoon with breezy/gusty west to northwest winds spreading across the region behind the cold front. The boundary layer thermal gradient tightens across our area as the cold front tracks through, which could promote more cloud cover, which could affect highs Wednesday. Still, any sun and the gusty winds should aid in mixing and high temperatures in the lower to mid 60s but around 70 to lower 70s south and some 50s in northern areas. That is potentially a big difference in temperatures form north to south but the tight boundary layer thermal gradient associated with the cold front will be right over us. && .SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/... Tight pressure gradient Wednesday night will lead to continued breezy conditions. Cyclonic flow and residual moisture will lead to some clouds and possible some snow showers over the southern Adirondacks. Lows Wednesday night area expected to be in the upper 20s to upper 30s. Thursday will be dry and breezy at times. Highs should be a few degrees cooler than on Wednesday, in the upper 40s to near 60. High pressure builds in for Thursday night with mainly clear skies expected. Lows Thursday night will be in the upper 20s to mid 30s, although if skies remain mostly clear, all areas may drop to near or below freezing. && .LONG TERM /FRIDAY THROUGH TUESDAY/... The period starts out on Friday with surface high pressure over the region with a dry northwest flow aloft. This should result in a tranquil day with near to slightly above normal temperatures. The high will drift eastward off the southern New England coast Friday night, but will remain in control of our weather providing dry and cool conditions. Lows Friday night in the 30s. Saturday should start out dry in eastern areas, but some showers are possible during the morning west of the Hudson River. Chances for showers will increase by afternoon from west to east as isentropic lift increases ahead of a warm front approaching from the west. Highest POPs are forecast over the southern Adirondacks and western Mohawk valley, but all areas may see some rain by sunset on Saturday. Highs saturday in the 50s and 60s. At this time Sunday does not appear to be a washout, although we will have to watch for potential showers and even some thunderstorms, especially during the afternoon/evening. Models indicating some instability developing in a general warm sector ahead of a cold front pushing south from Canada. Models also showing quite a bit of moisture in the warm sector. 850MB temps rise to around +12C. Cloudiness will modulate temperatures so areas that see sunshine could get quite warm. Latest guidance indicating valley locations from Albany southward could reach into the 70s before the cold front moves through Sunday night. Mainly drier, cooler and breezy conditions expected for Monday in wake of the cold front passage with gusty northwest winds and perhaps a few mountain showers. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... A cold front will slowly move southeastward across eastern NY and western New England tonight and through Wednesday morning. A weak disturbance moving along the front will produce some scattered showers. Drier weather will return in the wake of the front tomorrow afternoon. VFR conditions will be in place early this evening, but clouds will thicken and lower between 05Z-09Z from KGFl southward to KPOU with some showers moving in ahead of a cold front a weak disturbance moving along it. Cigs/vsbys will lower to MVFR levels especially between 08Z-12Z from KALB-KPSF northward with perhaps some IFR CIGS at KSPF btwn 10Z-17Z. The showers may reach KPOU by 12Z...and last until about 17Z. MVFR conditions should improve to VFR levels with the showers ending btwn 15Z- 17Z at KALB/KGFL/KPOU. Some lingering MVFR cigs will persist around 2 kft AGL at KPSF until about 20Z. Expect scattered to broken stratocumulus and high level clouds in the late afternoon in the wake of the front. The thunderstorm threat has diminished and has not been included in the TAFS at this time. The winds will back from the west to northwest at 5-10 kts to the southwest to south at 4 to 7 kts between 05Z-08Z. The winds will increase from the west to northwest at 10-15 kts in the late morning into the afternoon with some gusts in the 20-25 kt range at KALB/KPSF. Outlook... Wednesday Night to Thursday Night: No Operational Impact. NO SIG WX. Friday: Moderate Operational Impact. Chance of SHRA. Friday Night: Moderate Operational Impact. Chance of SHRA. Saturday: Moderate Operational Impact. Chance of SHRA...TSRA. Saturday Night: Moderate Operational Impact. Chance of SHRA. Sunday: Low Operational Impact. Breezy NO SIG WX. && .FIRE WEATHER... Gusty south to southwest winds to 20 mph expected this afternoon into this evening with RH values around 30 percent... A cold front will cross the region tonight, bringing a chance for showers and thunderstorms. Drier and much cooler weather will return for later Wednesday into Thursday with high pressure building into the region. Fair weather is forecast for Friday after a chilly start to the day. Relative humidity values will recover to 80 to 100 percent tonight night and drop to 50 to 70 percent on Wednesday. RH only recovers to 60 to 80 percent on Wednesday night. Winds will be west at 5 to 10 mph tonight and west at 10 to 20 mph on Wednesday. Winds will shift to the northwest Wednesday night and continue at 10 to 20 mph. && .HYDROLOGY... Warmer temperatures today will result in increased runoff due to snow melt. River levels will need to be monitored due to snow melt for basins with significant snow pack such as in the southern Adirondacks, upper Mohawk, upper Hudson and into southern Vermont. Scattered showers and thunderstorms this afternoon through Wednesday will result in basin average rainfall of a quarter of an inch or less but point rainfall totals could be up to a half inch. The following river point has a flood warning in effect: Riverbank (Schroon River). For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...SND/11/Wasula NEAR TERM...11/Wasula SHORT TERM...SND LONG TERM...SND AVIATION...Wasula FIRE WEATHER...SND HYDROLOGY...SND
Area Forecast Discussion
National Weather Service La Crosse WI
1100 PM CDT Tue Apr 11 2017 .SHORT TERM...(This evening through Wednesday night) Issued at 300 PM CDT Tue Apr 11 2017 Clouds have been very slow to erode and move out today as surface high pressure moves into the region. However, RAP low-level RH fields suggest clouds should finally start to dissipate and move from west to east late this afternoon/evening with all but the far east clearing out by sunset. With light surface wind, clearing skies, and moist low-levels, there is a chance for some patchy fog tonight along and east of the MS River. However, the light wind layer is rather shallow, so not expecting widespread development. Cloud cover increases rapidly Wednesday ahead of a fast moving short-wave aloft. An elongated surface trough develops from CO to central IA in response to this wave with a west-east oriented warm front in the vicinity of I-80. Models suggest two main areas of rain with this system late Monday afternoon and Monday night. The first is associated with isentropic lift/mid-level frontogenetical forcing across much of the forecast area. And the second is more closely tied to the surface warm front along the nose of the best 850-700 hPa moisture advection. Instability is weak overall with unfavorable low-mid level lapse rates, so any thunder should remain south of the forecast area. Precipitable water values do increase to around three quarters of an inch, resulting in rainfall amounts from 0.25-0.75 inches with the highest amounts south of I-90. Despite overcast skies, temperatures Wednesday will rise back into the lower 60s within broad warm air advection regime. .LONG TERM...(Thursday through Tuesday) Issued at 300 PM CDT Tue Apr 11 2017 Thursday will remain mostly cloudy, but lingering rain showers are expected to move out of the area through the day with 500 hPa ridging aloft and surface high pressure nosing south from Canada. Highs will top out in the mid 50s to lower 60s with light easterly wind. A broad trough moves into the intermountain west on Friday, allowing a short-wave to race northward into the Upper Midwest within southwest flow aloft. Still some timing differences between medium-range models with the ECMWF 6-12 hours faster than the GFS. However, general idea is for showers and thunderstorms to lift northward through the day and into Friday night within broad warm air advection regime. 0-3 km MUCAPE does increase up to 1000 J/kg by 06Z Saturday, but overall shear is rather weak (generally less than 30 kts), so not anticipating any severe storms at this time. Temperatures Friday will be in the 60s. Additional shower and thunderstorms are possible Saturday as a secondary northern stream short-wave swings a cold front across the forecast area. Instability and deep layer shear do increase through the day, but model soundings suggest there may also be capping issues. Too early to discern severe potential, but something to watch through the week. High pressure will dominate the regional weather pattern Sunday into Monday, resulting in partly sunny skies and dry weather. Temperatures will range from the mid 50s to mid 60s. Another chance for precipitation then moves in on Tuesday. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 1100 PM CDT Tue Apr 11 2017 Cigs: mostly skc/sct conditions through 12z, then increasing high/mid level clouds from the west Wed morning - associated with an approaching upper level shortwave trough. The cigs will continue to lower through 00z, likely holding VFR though through the period. Wed night should see a drop into MVFR/IFR, holding into Thu morning. VSBY/WX: t/td spread only 7 F at 03z at klse, and light sfc/near sfc winds through much of the night time hours, leads to some questions on the potential for valley fog. HRRR/RAP/NAM12 bufkit soundings hint at it for KLSE, but not enough to include in the forecast. Will continue to monitor. Otherwise, don`t expect any impacts til closer to 00z thu as the upper level shortwave/warm air advection/west-east running frontogenetic region results in areas of -shra for the region. Expect a drop to MVFR for Wed night as the rain sets in. Winds: generally light from the southeast, picking up and more southerly Wed before a slight shift back southeast Wed night. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ SHORT TERM...Rogers LONG TERM...Rogers AVIATION...Rieck
Area Forecast Discussion
National Weather Service Cleveland OH
933 PM EDT Tue Apr 11 2017 .SYNOPSIS... A cold front over the southeast counties will move off to the southeast this evening the high pressure will push east across the region late tonight into Thursday. A series of lows will move northeast along a front over the upper midwest late Friday through Sunday eventually pulling a cold front southeast across the area Sunday. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... Showers with the cold front continue to move east of the area at this time. Colder air continues to move east into the area in the wake of the cold front. Temperatures should continue to fall through the night in the cold air advection. Latest satellite imagery shows cloud shield advancing east and will be slow to clear out from west to east overnight. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY NIGHT/... The high will be shifting east across the cwa Wed into Thu and should keep conditions dry, but cooler into Thu with highs on Wed only from around 50 far ne to the lower 60s far sw. Lows Wed night should range from the mid 30s east to the lower 40s west. Temps Thu should moderate a few degrees warmer as winds veer to east to se to no longer be coming off the chilly lake. Moisture from the next system will be returning Thu, focused by a warm front that lifts into the cwa. There is a small chance a shra could occur in the north Thu into Thu night as an upper s/w drops ese across the area providing enhanced forcing. Lows Thu night will not be as cool as the previous few nights. The next s/w should ride ne from the southern plains to be near NW OH by 12z sat. The added energy from this upper system should bring a batch of shra/tsra east into the cwa Fri night. Temps will continue to trend warmer Fri and Fri night as the warm front lifts further north. && .LONG TERM /SATURDAY THROUGH TUESDAY/... Warm front will lift across the region on Saturday with a chance of thunderstorms near it. The region will then be in the warm sector at some point Saturday afternoon into Sunday afternoon. So another round of thunderstorms will be possible as a cold front moves west to east across the region Sunday afternoon and evening. Cooler on Monday in the wake of the cold front. Saturday looks to be the warmest day of the long term with highs well into the 70s for most locations. Cloud cover and developing thunderstorms should limit the heating slightly on Sunday with highs within a couple degrees of 70s. Cooler Monday with highs closer to seasonal averages. && .AVIATION /00Z Wednesday THROUGH Sunday/... A bit of a quandary the next 12 hours or so as guidance diverges. The cold front which has passed through all but KCAK and KYNG will move southeast out of the area early this evening with winds turning wnw behind the boundary. Conditions behind the front will be VFR to start. Guidance then diverges with the NAM leaning more toward MVFR CIGS developing through the night vs mostly VFR with the GFS as high pressure builds in. High resolution HRRR also supports VFR cigs. In short dont fully trust that MVFR CIGS dont develop in the post cold front airmass overnight. For now will allow for an MVFR CIGS for a couple hours this evening northwest given proximity to the deck as MI. Will then continue a low VFR cigs through the night. Will also have an MVFR CIG around dawn KMFD. Further east low level moisture actually pivots into the area affecting primarily KERI after 08z. Will have and MVFR CIGS at in a tempo group to start at KERI and again at 10-14z. For the balance of Tuesday am expecting VFR. OUTLOOK...Non-VFR possible Friday night into early Saturday. Non-VFR possible in showers/thunderstorms on Sunday. && .MARINE... Cold front moving across the western basin of Lake Erie should clear the east end of the lake by midnight. Westerly winds will become more from the northwest toward sunrise. Waves may briefly touch 3 to 5 feet across the east end of the lake overnight but it will be brief so we will hold of on a small craft advisory. High pressure will then take control of the lake on Wednesday with light winds. As the high shifts eastward and a warm front moves toward the lake Thursday into Friday northeast to east winds will increase. This flow may persist long enough to build waves across the western basin for the end of the week. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...None. && $$ SYNOPSIS...Adams NEAR TERM...Lombardy SHORT TERM...Adams LONG TERM...Mullen AVIATION...TK MARINE...Mullen
Area Forecast Discussion
National Weather Service State College PA
1031 PM EDT Tue Apr 11 2017 .SYNOPSIS... A cold will move across Pennsylvania this evening and overnight. Dry and cooler conditions will follow for Wednesday through Friday under a ridge of high pressure. && .NEAR TERM /UNTIL 7 AM WEDNESDAY MORNING/... Frontal analysis by WPC puts the front somewhere over the NW counties, and drier with NW wind direction does appear there now. The front should move slowly SE through the night. However, the pressure pattern is warped by the current meso high under/behind the current area of showers. Vort max is working through the CWA and is just about over Happy Valley. The few CGs associated with the TS right under it have all but died out. The rain filled in nicely, but it is still pretty light. HRRR/RAP play up a scenario where the focus for showers remains along this same axis from IPT-JST - mainly to the NW of MDT and SE of FIG - through much of the night before pivoting and sliding closer to MDT. However, precip may never reach into LNS. Will keep just a 20 POP there for the night, but keep them high-ish between MDT and FIG. Convection in the OH valley is still headed this way, but may not survive the trip across WV as a cold outflow boundary has been pushing south from the earlier convection and should contribute to an overall increase in stability. Prev... Instability still trying to work up to the very high LFC, and just a few showers have been going on thus far this evening. However, a nice connection between some showers in the E and the SW ahead of a decent short wave trough in srn OH is developing. Will keep POPs in the high-chc very low likely range for the central counties this evening. temps still very warm and RHs still pretty low with 40s widespread. Thus, bases are very high (for Central PA standards) and not a lot of precip has reached the ground at this point. A nice rainbow out the window a few mins ago was most likely a virga-bow with dbZs only in the m30s in those showers over Mifflin Co. Prev... As of mid day the cold front extended from a low over southern Ontario down through central Ohio. The leading edge of showers was trekking through the Northern Mountains. Latest lightning data shows that the thunderstorms have moved into NY. But the atmosphere remains marginally unstable with mid level lapse rates exceeding 7C/KM covering most of PA and a few hundred joules of CAPE being analyzed depending on what the near term model of choice is. Models show a narrow ribbon of enhanced moisture pooling up ahead of the approaching front helping support some modest destabilization. Local dewpoints in the 40s will climb into the u40s and mid 50s in advance of a cold front later today across the western half of the state, and continue across the remainder of the region this evening and overnight. SPC has confined the Day 1 Marginal Risk to north of the NY/PA border, closer to the nose of the upper jet. Most of PA is forecast to remain under the relatively unfavorable right front exit of this jet. Latest HRRR kills most of the shower/thunderstorm activity as it moves into central PA toward nightfall, before bringing a new surge of showers up over the forecast area during the late evening into the wee hours of Wednesday. While forecast surface based LI`s suggest the boundary layer stabilizes as the sun goes down, mid level lapse rates are forecast to be relatively steep, exceeding 6C/KM along the front as it slides across later tonight. So a nocturnal thunderstorm cannot be ruled out with the passage of the front. Highs today are generally overachieving in the sunny wedge east of the cloud mass covering the NWRN 1/2 or so of my CWA. I nudged things a tad higher than the blended MOS yielding 80 or above for much of the eastern portion of my forecast area. It will remain mild overnight with lows some 10-20 deg above normal. && .SHORT TERM /7 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/... Models agree that the cold front will either be just leaving far SERN Lancaster county around sun rise Wednesday or will already be east of the area. The last of some lingering rain showers will be similarly exiting the region leaving the bulk of Wednesday dry with brightening skies. All model guidance concurs on a nice, but moderately cooler Wednesday. Highs in the 50s to around 70 will still average several degrees warmer than normal. && .LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... Model and ensemble guidance are in pretty good agreement on the overall pattern and sensible weather impacts through the period. Seasonal temperatures through the end of the week will trend warmer over the weekend, likely reaching a pre-frontal maximum on Easter Sunday before cooling off modestly into early next week. Dry conditions are expected through Friday with an increasing risk for rain showers over the weekend before the area drys out again next Monday/Tuesday. In terms of fcst details, there is not much to target/highlight. Shortwave energy embedded within a low amplitude trough exiting the Northeast U.S. streaks through the Upper OH Valley and Northern Mid Atlantic later Thursday into Friday while a frontal boundary sets up from the Mid MS Valley eastward through the Delmarva. Some pcpn may focus along the frontal zone but high pressure should keep it confined to the south/west of PA. The boundary then pivots northward as a warm front on Saturday as an upper ridge builds over the Southeastern U.S. It appears the main focus for showers and perhaps a few thunderstorms is with a cold FROPA on Sunday. Hedged Sunday max temps above NBM/ECENS blend with a mild SW flow ahead of the approaching cold front. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... A weak cold front is now nudging into far Northwest Pennsylvania this evening at 00z. Weak but discrete band of showers just to the east of Erie seems to depict the front and wind shift line well. Area of light showers, and at 00z one isolated thunderstorm near Somerset, in advance of the front. HRRR has consistently been handling precipitation well this evening. This model depicts the area of showers to hang in across the Central Mountains through about 07z, before weakening later in the overnight. HRRR also not producing much precipitation with the actual front, but continues to hint that scattered showers will accompany FROPA overnight. Lower ceilings have begun to break out across the Western Mountains, and this trend will continue post-frontal as winds shift to the west-northwest. Moisture from the pre-frontal showers, combined with upslope flow, will bring IFR conditions to KBFD and KJST overnight...with some guidance suggesting a period of LIFR ceilings. Over central airfields, expect some MVFR conditions with the showers and frontal passage overnight. Areas in the southeast will likely remain VFR with just a passing shower after 06z. Clearing trend begins mid Wednesday morning, with all airfields back to VFR by early afternoon. As previous TAFs indicated, have not included thunder, with low likelihood and coverage. Will have to watch KJST/KAOO though, following radar persistence for the lone TSRA cell. VFR conditions for the entire region by late morning/early afternoon through the end of the week. Outlook... Thu-Fri...No sig wx expected. Sat-Sun...Sct showers. Restrictions poss NW. && .CLIMATE... A daily record high temperature of 86 degrees has been set today at Williamsport. This breaks the old record of 82 degrees set in 1922. A daily record high temperature of 86 degrees has been set today at Harrisburg. This breaks the old record of 84 degrees set in 2011. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...La Corte NEAR TERM...Dangelo/La Corte SHORT TERM...La Corte LONG TERM...Steinbugl AVIATION...Jung CLIMATE...
Area Forecast Discussion
National Weather Service Duluth MN
942 PM CDT Tue Apr 11 2017 .UPDATE... Issued at 942 PM CDT Tue Apr 11 2017 Skies have cleared across the Northland this evening. We lowered temperatures a bit in spots and increased them late in the Brainerd Lakes/Leech Lake area. There were some showers moving through eastern North Dakota and there is some concern they could hold together and affect our western CWA after 08Z. The latest NAM does bring some QPF into our southwest area and the HRRR also shows some showers late. However, the airmass ahead of these showers is quite dry and the leading edge of the precipitation was diminishing some. Several of the other models show the precipitation remaining west of our area. We did increase cloud cover a bit but left the mention of precipitation out for now. A light mix would be possible depending on how quickly surface temperatures respond to the increase in clouds. UPDATE Issued at 623 PM CDT Tue Apr 11 2017 Please see the 00Z Aviation Discussion below. && .SHORT TERM...(This evening through Wednesday) Issued at 332 PM CDT Tue Apr 11 2017 The upper level weather map features a broad low pressure trough over southeastern Quebec and into the MN Arrowhead while another shortwave trough was enter North dakota late this afternoon. The eastern trough will gradually pull away tonight and as it does surface high pressure will build into the region and help scour out the clouds that have been linger over northwestern Wisconsin. With the high over the region and very light winds, temperatures will drop quickly after sunset. Lows in the teens could be seen again in the Arrowhead while 20s elsewhere. Some dewpoints in the Arrowhead have been in the single digits this afternoon, so will need to watch and maybe lower forecast minimums. But, an increase in clouds from the Dakotas shortwave could keep temperatures from following too fast. On Wednesday the surface high will move east out of Wisconsin. A return flow from the south will help boost temperatures into the 50s. Another shortwave that will be moving across South Dakota and across southern Minnesota will spread could northward Wednesday afternoon with just a slight chance of showers over our extreme southern portions of the forecast area. .LONG TERM...(Wednesday night through Tuesday) Issued at 332 PM CDT Tue Apr 11 2017 The models are in good agreement concerning an upper level shortwave that will slide across southern Minnesota and into central Wisconsin Wednesday night and early Thursday. This shortwave will bring a chance of light rain to southern portions of the Northland, especially along our southern border. As the shortwave moves off to the east, upper level heights will build considerably to the west. This should provide dry weather for Thursday afternoon and evening, before an upper level shortwave in southwest flow pushes quickly into the Upper Midwest and western Great Lakes. Showers and thunderstorms should push northward on Friday, with showers and thunderstorms continuing Friday night and Saturday. The best chance for thunder will be in the southern and southeastern portions of the CWA, but will be possible just about anywhere due to the strength of the upper level shortwave and rapidly decreasing stability. An upper level trough will then settle into the region Saturday night and Sunday, bringing cooler and unsettled weather for the remainder of the weekend and into early next week. Temperatures will cool considerably over the weekend and into early in the week, especially at night, with some snow possible. Another strong system is expected to move into the Northland Monday night and Tuesday, with another high chance of precipitation across the region. The models are actually in good agreement considering it is a week out. Temperatures will climb into the 60s by Saturday, and then cool considerably to the 40s to low 50s for highs by Monday and Tuesday. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 623 PM CDT Tue Apr 11 2017 VFR through the upcoming TAF cycle. High pressure will build across southern MN/WI tonight into Wednesday, before sliding into the Central Great Lakes. Behind the high, a shortwave trough will dig into the Northern Plains. This will gradually spread light near KHYR/KBRD by the end of the TAF period. Winds will remain less than 10 knots through the forecast per the NAM/DLHWRF and latest MOS guidance. && .PRELIMINARY POINT TEMPS/POPS... DLH 27 56 37 56 / 0 10 10 10 INL 22 59 32 62 / 0 10 0 0 BRD 32 60 38 62 / 10 20 10 0 HYR 25 57 38 59 / 0 10 30 10 ASX 25 57 35 56 / 0 10 20 10 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. LS...None. && $$ UPDATE...Melde SHORT TERM...CLC LONG TERM...DAP AVIATION...WL
Area Forecast Discussion
National Weather Service Jacksonville FL
858 PM EDT Tue Apr 11 2017 .UPDATE... Not much change to the forecast as weak high pressure ridging remaining north of the region with an easterly steering flow across NE FL/SE GA. Evening JAX sounding shows PWAT up just slightly to 0.72", so atmosphere has just slightly more moisture but despite this, still do not expect much in the way of shower activity, at most a few sprinkles across the Atlc Coastal Waters, and just a slight chance of patchy fog over inland areas of SE GA and North FL along the I-10 corridor with the SREF showing 20% chances of FOG and HRRR showing a few spots of 1-5 mile fog possible just inland from the JAX-BQK corridor but still not likely significant enough to include in the forecast. Expect lows in the 50s inland and near 60 along the coast. Expect another day of partly sunny skies in the morning on Wednesday as fair weather cumulus develops in the easterly flow then advances inland as the Atlc Coast sea breeze marches inland with sustained winds of 10-15 mph and temporary gusts to 20-25 mph at times. Highs remain similar to today with Max temps in the mid/upper 70s along the coast and lower/middle 80s well inland. && .AVIATION... Still mainly VFR through the next 24 hours. Low chances for MVFR fog at inland TAF sites, and have placed TEMPO 5SM at KVQQ. Otherwise some possible SCT clouds around 2500 ft still possible to push into the coastal TAF sites towards morning, then as heating begins during the morning hours some BKN CIGS around 3500 ft possible at TAF sites until mixing and sea breeze scatters out the clouds around 4000 ft after 18z. && .MARINE... No changes with East flow generally in the 10-15 knot range and seas 2-4 ft, although some slightly higher winds/seas possible in the NE FL offshore waters. Rip Currents: Moderate risk in the onshore flow. && .PRELIMINARY POINT TEMPS/POPS... AMG 55 82 55 82 / 0 0 0 0 SSI 62 74 62 76 / 0 0 0 0 JAX 56 79 57 78 / 0 0 0 10 SGJ 61 77 62 76 / 0 20 0 10 GNV 55 81 54 81 / 0 0 0 0 OCF 55 83 56 82 / 0 0 0 0 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. && $$ Hess/Nelson/McGinnis
Area Forecast Discussion...UPDATED
National Weather Service Memphis TN
934 PM CDT Tue Apr 11 2017 .UPDATE... Isolated/scattered areas of light rain showers will continue east of the MS River into the early overnight. Latest rapid update models appeared to have a good handle on rain. GOES IR imagery showed clouds clearing to the west of the MS River. HRRR suggests patchy fog likely overnight over the MS delta southwest of Memphis. SREF is in general agreement, while maintaining a 50 percent probability of < 1 mile surface visibility further north, near the I-40 corridor. Will continue a mention of patchy overnight fog in these areas. PWB && .PREV DISCUSSION... /issued 700 PM CDT Tue Apr 11 2017/ UPDATE... Updated to include 00Z aviation discussion below. PREV DISCUSSION... /issued 330 PM CDT Tue Apr 11 2017/ DISCUSSION... The cold front continues to move slowly through the Mid-South this afternoon. Winds are from the north and northwest across most of the area, but tightest moisture gradient roughly mirrors the I-40 corridor. Showers have increased in coverage over the past few hours, becoming a bit more organized and producing a few lightning strikes over west TN in recent volume scans. The potential for strong storms will remain low this afternoon given the muted instability and weak vertical shear. Temperatures don`t look to warm much more this afternoon and will likely cool a bit in areas experiencing rainfall. Showers will continue through the evening hours, waning overnight as the front continues south and the shortwave trough moves east. Farther north, patchy fog will be possible in areas where skies are able to clear. Expect overnight lows generally in the 50s. Generally dry conditions are anticipated on Wednesday and Thursday, but a few diurnal showers and thunderstorms will be possible across portions of north MS. Coverage should remain limited should any convection develop. Afternoon highs tomorrow will be in the upper 70s and lower 80s, with most of the Mid-South reaching the 80s on Thursday. Low temperatures will generally range from the mid 50s to lower 60s. The Mid-South will remain under at least some influence of a low- amplitude mid-level ridge through the weekend. As one wave lifts northeast over this ridge on Friday, a few showers and thunderstorms will be possible. Again, coverage should be limited and most areas will remain dry. Generally dry conditions are anticipated on Saturday, but rain chances return to the area Saturday night and Sunday as a cold front moves south into the region. Most of the dynamics will be well removed to the north of the CWA and vertical shear will be weak. Thus, organized severe weather is not anticipated. Rain chances continue area wide early next week as this front stalls beneath quasi-zonal flow aloft. High temperatures over the weekend will range from the mid 70s to mid 80s with overnight lows in the upper 50s and lower 60s. Johnson && .AVIATION... 00Z TAF Set An broken line of slow moving showers behind a frontal zone will affect MEM...MKL...and TUP in the short term. For now all sites are VFR, with the exception of MKL where MVFR ceilings exist. Short term models indicate this band of rain exiting all sites after 12/07Z or so, with heavy rain possible at MKL. If skies clear behind this line of showers, MVFR and IFR conds will be possible at all sites due to fog and low stratus around midnight or so. At this time, confidence remains about 60% that a low stratus deck, IFR deck, will materialize at MEM after 12/06Z for which a tempo group was added. All sites will return to VFR by late morning as surface high pressure builds in from the west. AC3 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$
Area Forecast Discussion
National Weather Service Miami FL
815 PM EDT Tue Apr 11 2017 .AVIATION...Lull in SHRA activity currently, with chances increasing along east coast 07Z-09Z as moisture surge moves in from Bahamas. VCSH for all east coast sites after this time through TAF cycle, though activity may shift a little more inland after 18Z. Gustiness diminishes after 01Z, though east coast sites remain 10-12kts through the night, becoming 15G22kts after 13Z- 14Z. Unsure if Gulf breeze will reach KAPF tomorrow, but trending to site becoming WNW after 19Z. Additional SHRA vicinity KAPF after this time with seabreeze convergence. && .UPDATE... Latest IR satellite imagery shows a distinct surge of moisture moving from east to west across the Bahamas. This feature will be our main player for our weather during the next 24-hours. Clockwise flow from surface high pressure to the north will drive this moisture towards southern Florida, approaching the coast by Wednesday morning. The HRRR and Hi-Res WRF indicate increasing chances of precip starting by around sunrise along the east coast metro region. Have adjusted PoPs accordingly. Tomorrow afternoon, forecast GFS SB CAPE values are between 500-700 J/KG and LIs around -2C. Although a few strikes of lightning can not be ruled out, confidence is too low to add to the grids on this update. Otherwise, breezy easterly winds will continue overnight, mainly along the Atlantic coastline. Smoke from the Cowbell fire may cause periods of low visibility along portions of I-75 in interior Collier County. && .PREV DISCUSSION... /issued 428 PM EDT Tue Apr 11 2017/ DISCUSSION... Through tonight: Latest water vapor imagery shows troughing along the central CONUS with upper level ridging stretching from the eastern Gulf to the western Atlantic. South Florida continues to reside on the southern side of an elongated surface ridge to the north. Clockwise flow around this feature brought easterly winds to South Florida this afternoon, mainly in the 10 to 20 mph range. Low level moisture advecting westward from the Atlantic will generate light showers along portions of the eastern peninsula this evening. However, as the air moves across the landmass, it becomes much drier. Min RH values this afternoon ranged from generally 50 to 60 percent along the east coast metro down to 30 to 40 percent over portions of Collier, Hendry, and Glades counties. Thus, to account for this trend, a Red Flag Warning was issued for these locations. The coolest weather has occurred along the east coast metro, where onshore flow only allowed max temperatures to top out in the upper 70s/lower 80s. Further west, max temperatures have been higher, in the mid 80s, as it typical for an easterly flow pattern. Tonight, persistent moisture advection from the Atlantic will keep temperatures from falling much below 70 degrees along the east coast metro. Minimum temperatures may lower to the upper 50s to lower 60s across the interior and Gulf coast, where drier air and better radiational cooling will occur. Tomorrow through Thursday: Surface high pressure will remain in control over the Western Atlantic the next several days, continuing the easterly flow pattern across South Florida. Both the GFS and ECMWF push a surge of lower level moisture, currently located near the Bahamas, over our region Wednesday morning through Wednesday night. This increase in moisture, along with diurnal heating should trigger scattered showers across the entire CWA, with highest probability over the east coast metro and interior regions. Forecast CAPE and other instability factors are minimal, so not expecting any convection to develop. By Thursday, models push the moisture to the the southwest over the Gulf, once again decreasing shower activity over southern Florida. Maximum Wednesday and Thursday afternoon are forecast to range from the upper 70s/low 80s along the east coast metro to mid 80s across the western interior, which is near normal for this time of year. Friday through this weekend: Stronger high pressure to the north will allow surface pressure gradients to tighten, bringing an increase to the easterly flow...especially on Saturday. Otherwise, status quo with temperatures near normal and scattered light showers, mainly at night along the east coast metro. MARINE...Moderate to fresh easterly winds will continue throughout the forecast period as a ridge of high pressure remains in place north of the area. Speeds will generally 15-20 knots with seas 4-6 feet, sufficient for small craft to exercise caution. Seas may increase to 6 to 7 feet along the Gulf Stream by Wednesday afternoon. Easterly winds will increase near Small Craft conditions early this weekend. BEACH FORECAST...Moderate and occasionally gusty easterly breezes will continue, keeping the rip current risk level high through this evening. Moderate to strong rip currents will likely occur through the rest of this week as easterly flow persists. FIRE WEATHER...Surface high pressure to the north of the region will lead to persistent easterly winds across south Florida over the next several days. Expect very good to excellent dispersion most afternoons. Isolated light showers will develop along the east coast metro region with drier conditions further west. There will be a increase in clouds and showers tomorrow and Friday. Latest forecast trends show a slight increase in RH tomorrow, with min RH values ranging from 45 to 55 percent in the western interior. The Red Flag Warning over Glades, Hendry, and interior Collier counties is set to expire at 8pm this evening. && .PRELIMINARY POINT TEMPS/POPS... West Palm Beach 70 79 69 79 / 20 40 30 20 Fort Lauderdale 71 80 70 79 / 30 40 30 20 Miami 70 81 69 80 / 30 40 30 20 Naples 64 82 64 83 / 10 30 20 30 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...Red Flag Warning until 8 PM EDT this evening for FLZ063-066-070. High Rip Current Risk until 8 PM EDT this evening for FLZ168-172- 173. AM...None. GM...None. && UPDATE...27/JT AVIATION...88/ALM DISCUSSON...27/JT MARINE...27/JT BEACH FORECAST...27/JT FIRE WEATHER...27/JT
Area Forecast Discussion
National Weather Service Norman OK
830 PM CDT Tue Apr 11 2017 .UPDATE... Low level moisture will make a return north overnight. This will likely lead to stratus deck overspreading the area and the possibility of patchy fog. Therefore have added some fog to the forecast late tonight into the first part of the morning across much of the area. Otherwise, only very minor tweaks to going forecast. 30 && .PREV DISCUSSION... /issued 643 PM CDT Tue Apr 11 2017/ AVIATION... VFR conditions are expected through about 8-9z with a light/moderate east to southeast wind. IFR conditions may develop at most TAF sites during the late overnight into early Wednesday morning as moisture returns. A recent run of the HRRR lowers visibility below 1/2 mile across part of western north Texas and a large part of western Oklahoma between 11-13z. For now, will reduce visibility to around 2 miles with ceilings around 500-700 feet. Ceilings and visibility should improve to at least MVFR conditions by 16z. PREV DISCUSSION... /issued 350 PM CDT Tue Apr 11 2017/ DISCUSSION... Primary forecast focus is on increasing rainfall chances Wednesday evening through Thursday, beginning across western north Texas into western Oklahoma. Anyone else in Oklahoma or western north Texas feeling the "patio vibes" today? Seriously, it`s in the upper 60s and low 70s with a light wind, the "get outside" advisory is in effect through the evening. Overnight, low clouds will gradually increase in coverage across the region, from the Red River to the north. Looking at various Bufr profiles, not quite sold on fog development across southern Oklahoma and western north Texas, given boundary layer winds and dew points, I am inclined to lean toward stratus developing across the region late tonight, lingering through Wednesday morning. This will impact low temperatures overnight, depending on when clouds develop and the impacts of any insolation. Tried to highlight this with morning lows, keeping them a tad warmer across the southern half of Oklahoma into north Texas. Through Wednesday, brief 500mb ridging will give way to the approach of an open, yet defined, short wave trough lifting east/northeast off the high plains of New Mexico and the Llano Estacado. You can make out this feature on all three GOES-16 water vapor channels, it`s currently pushing ashore on the Baja Peninsula and southern over southeast Oklahoma and TeCalifornia. Ahead of this trough, low level moisture will continue to pool across west Texas into the Texas Panhandle and southwestern/western Oklahoma. A fairly broad area of isentropic ascent will reside within this same sector, providing the focus for developing scattered to numerous showers and thunderstorms. Convection, Wednesday, will likely be ongoing by midday across the higher terrain of New Mexico, across the Sangre de Cristos and south along the Sandias. This activity will gradually build eastward through the day, across the Caprock Canyonlands and interact with developing activity within the warm sector across western north Texas and finally western Oklahoma into the evening hours. There is a marginal risk for a few strong to severe storms in far western Oklahoma, due to modestly steep mid-level lapse rates and modest CAPE and shear, so a few hailers cannot be ruled out. Overall, moderate to heavy rainfall is what can be expected, with over southeast Oklahoma and Teamounts building steadily overnight through Thursday. The heaviest amounts are expected between 1.50 to 2.25 inches, with some isolated areas getting closer to 3 inches. The area affected will be portions of western north Texas, into southwest and western Oklahoma into north central Oklahoma. Flooding and flash flooding potential is fairly low, as rainfall will be spread over several hours, for most of Thursday. However, initial development and any training of storms could result in some marginal flooding concerns, especially across western north Texas into southwestern Oklahoma. Rain chances will end through Friday, with lingering showers and thunder through the morning across northern Oklahoma. Rain chances will return over the weekend, Saturday evening through Sunday as a over southeast Oklahoma and Tecold front moves into the region from the north. Kurtz && .PRELIMINARY POINT TEMPS/POPS... Oklahoma City OK 51 75 59 73 / 0 10 50 50 Hobart OK 47 73 59 71 / 0 20 70 70 Wichita Falls TX 52 77 60 76 / 0 20 50 40 Gage OK 48 71 56 69 / 0 40 70 70 Ponca City OK 49 76 59 73 / 0 0 30 60 Durant OK 59 77 60 78 / 0 10 10 20 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...None. TX...None. && $$ 30/06
Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
745 PM EDT Tue Apr 11 2017 .UPDATE... 00Z water vapor and H4 RAP analysis shows a benign weather pattern in place over the Florida peninsula...and this pattern will be our weather through the middle of the week. Weak amplitude ridging extends aloft from the central/eastern Gulf of Mexico...over the state of Florida and has provided the large scale suppression today to keep our cumulus fields shallow and suppressed...and generally prevented any shower activity within our forecast area. These dry conditions will continue through the overnight hours into Wednesday morning. BKN clouds along the coast from Tampa Bay southward are a result of the broad speed convergence at the coast with the sea-breeze that tried to come inland today...but generally stalled near the beaches. As diurnal heating decreases from here forward...this low level convergence zone will weaken as well...and should see this cloudcover break up and/or move slowly out to sea with the prevailing synoptic easterly flow. As we head through the daylight hours of Wednesday...the upper ridge will begin to break down as shortwave energy evolves slowly eastward along the northern Gulf Coast. While this energy will not directly impact our region Wednesday...the loss of strong suppression aloft will produce an environment a bit more condusive to brief afternoon pop-up showers. The environmental flow looks to again prevent much inland penetration of the sea-breeze, but most of the hires guidance members are showing at least a speed convergence zone developing along the coast after 18Z. This zone will likely host a few showers as we head deeper into the afternoon. Rain chances are going to stay low 20-30%...and anything that does form will not be a drought- buster. Still...a few of you might need to briefly turn on the windshield wipers during the commute home tomorrow evening from the I-4 corridor southward. && .AVIATION (12/00Z through 13/00Z)... No significant aviation concerns anticipated though the TAF period. VFR conditions forecast to prevail through the overnight/morning hours of Wednesday. Low level winds appear steady enough to potentially prevent sea-breeze from making inland penetration more than a couple miles on Wednesday...and therefore keep winds at all terminals either east or northeast. A sprinkle/shower possible along the I-75 corridor after 20Z Wednesday, but any rainfall will be light and brief. Low potential for precip will keep mention out of current TAF package. && .Prev Discussion... /issued 255 PM EDT Tue Apr 11 2017/ SHORT TERM (Tonight - Wednesday)... Upper level ridging from the Gulf extending northeast across Florida and up along the eastern seaboard will remain in place through Wednesday, but will weaken some on Wednesday as a short wave trough moving across the southeastern states impinges upon it. At the surface high pressure offshore the mid Atlantic coast will remain in place through the period with an easterly wind flow continuing across the entire forecast area. A dry subsident air mass will keep rain out of the forecast tonight, however on Wednesday less suppression from the upper ridge combined with enough low level moisture may support some low-topped showers within the easterly flow across central interior and across southwest Florida during the afternoon where the best moisture will reside and have included a low pop mention (20 percent) in these areas, otherwise dry weather will continue. Temperatures tonight will run near seasonal norms with lows in the upper 50s to lower 60s. Highs on Wednesday with continue to run a few degrees above normal with highs climbing to around 80 to the lower 80s along the coast, and mid 80s inland. LONG TERM (Wednesday Night - Tuesday)... An upper trough will be moving over the state Wednesday night and Thursday as a surface cold front stalls and dissipates to the north of the state. High pressure and upper ridging will then build over the region and remain through Tuesday. Winds will generally be from the east/northeast through the period, with some evening surges possible. Conditions will remain mostly dry through the period, with just an isolated rain chance Thursday afternoon and then again for Tuesday afternoon. Temperatures will be above normal through the period. MARINE... Surface high pressure offshore the mid Atlantic coast of late will get reinforced by another ridge of high pressure moving offshore the northeastern states late in the week and during the upcoming weekend. The high will maintain an elevated easterly wind flow (10 to 15 knots near shore and around 15 knots offshore) over the Gulf waters through the period with cautionary wind surges (in the 15 to 20 knot range) likely over the offshore waters during the evening and overnight time frames. FIRE WEATHER... Sufficient low level moisture will keep humidity values above critical levels through the end of the week, so despite some high ERC values in some locations Red Flag conditions are not expected through the period. && .Preliminary Point Temps/PoPs... TPA 64 82 65 82 / 0 10 10 10 FMY 63 83 65 84 / 10 20 10 20 GIF 62 82 63 82 / 0 10 10 10 SRQ 62 81 64 83 / 0 10 10 10 BKV 58 83 59 82 / 0 10 0 10 SPG 66 80 67 82 / 0 10 10 10 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...None. Gulf waters...None. && $$ UPDATE/AVIATION...Mroczka Previous Discussion...McMichael/Hubbard