Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/11/21

Please see the 00Z aviation forecast discussion below.

AVIATION... Convection continues across the Rio Grande plains this evening, with most of the activity well south of DRT. We will monitor the need to add a mention of TSRA at DRT, but at this time we will leave that out of the forecast. Additional showers may develop late this evening into tomorrow morning, but the afternoon hours look favored for more widespread showers and thunderstorms. PREV DISCUSSION... /ISSUED 159 PM CDT Mon May 10 2021/ SHORT TERM (Tonight through Tuesday Night)... Severe storms with large to potentially giant hail possible west this evening... A stalled cold front draped across the region from west to east, with ample southerly flow at low to mid levels bringing rich moisture into the region above it, are setting the stage for severe storms this afternoon and evening, primarily west of US-281. A corridor of 4000+ J/kg MUCAPE as analyzed by the RAP exists along the Rio Grande, with 2500+ J/kg across the rest of south-central Texas. Although the 18Z DRT special sounding still showed a decent capping inversion, the expectation is that this will still mostly erode away through the rest of this afternoon with a little help from a weak shortwave and a brief window for some surface heating. Deep shear of 40-50+ knots, highest NW, will be in place this evening. Rotating storms are a high likelihood, and in this environment we are yet again under the gun for the potential of very large or even giant hail this evening over our western counties. Damaging winds are a secondary threat. The sfc front will sag very slowly southward through tonight, and there is a very low risk for a tornado south of it this evening as SRH increases due to the LLJ formation, but in general concern is very low for tornadoes. Despite the marginal risk in place over the east half of our area for severe storms, current local thinking is that storm chances are quite low for at least areas northeast of La Grange to Fredericksburg for this first event. Concern for localized flash flooding may be slightly increased this evening for primarily the Winter Garden region. With freezing levels maxing out around 12-13kft and then falling closer to 10 kft by Tuesday night, warm rain processes will occur but rainfall rates shouldn`t be off the charts or anything. Rivers have had plenty of time to subside since the heavy rainfall late April into early May so river flooding is not of much concern. However, impacts such as ponding on roadways or overflowing culverts could be seen in a few places where heavier rains do occur with a couple hours of residence time. Somewhat more impactful flash flooding could be possible across our western CWA this evening. The 12Z WRF-NMM, for example, puts out a bullseye of 4+" of QPF over Uvalde and Zavala counties, and the HRRR suggests the potential for similarly high QPF over the Winter Garden region. That area is the most parched overall, especially along our southern border, so they can take a bit of rain, but will have to keep a close eye on things today. Storms will likely cluster and weaken overnight tonight over the southwest half of the CWA. However, redevelopment of showers and storms is anticipated Tuesday morning with off and on activity throughout the day and much of the night. Nailing down timing and location of storms is difficult but in the AM, chances will be best over the northwest half and will eventually spread across the rest of the area through the day. A broad-brushed marginal risk of severe weather, primarily for large hail, will be in place. A marginal risk of excessive rainfall is also in place across the area, although storms should be relatively progressive so we aren`t likely to see many localized totals during the day above the 1-3" range, if at all. That said, given the antecedent wetness over some spots and ample atmospheric moisture available as PWATs of 1.5-2" are still progged over all but the northern Hill Country, we will still need to keep an eye out for some localized flooding problems should heavier rainfall rates arise. With the cloud cover and rain in place and the front stalled near our southern border, rather cool temperatures are forecast, topping out only in the 70s north and low to mid 80s south/along the Rio Grande Tuesday. LONG TERM (Wednesday through Monday)... Our active weather pattern for the start to middle of the week should come to an end by Thursday, but not before we squeeze out another round of scattered showers with a few rumbles of thunder on Wednesday. A weak mid level shortwave will move through from west to east on Wednesday, resulting in some scattered showers and storms, especially within an east/northeasterly sfc flow regime. Any remnant rain showers should come to an end shortly after sunset on Wednesday evening, mainly over the southern 1/3rd of the CWA. South-Central Texas will be left under light northeasterly sfc flow on the southern periphery of a weak sfc high as it settles in to our north and east on Thursday afternoon. This should set the stage for several cool mornings, with many places in the mid to upper 50s, along with areas to the west and south in the lower to middle 60s. By late Friday, the sfc high will begin to retreat and slide eastward, allowing sfc flow to turn back out of the south, with sfc moisture returning as well as the Gulf of Mexico opens back up for business. The weekend looks to bring the return of a slightly more active pattern back into the picture once again. Models are somewhat divided on what will transpire by the start of next week, but are more in agreement on the setup for the weekend. Two separate shortwaves will ripple through the flow out ahead of a deepening long wave upper level trough over the southwestern CONUS. This will allow isolated to scattered showers and thunderstorms to develop both Saturday and Sunday afternoons. At this time, the threat for severe weather looks quite low, however, will continue to monitor the possibility of strong to severe storms by Sunday afternoon and Monday afternoon, as this type of pattern has led to severe weather in our region over the last several weeks. PREV DISCUSSION... /ISSUED 1248 PM CDT Mon May 10 2021/ AVIATION... CIGs are hovering just below MVFR thresholds at SAT this afternoon but should lift to VFR for a time. AUS is seeing a brief clearing but it isn`t expected to last. Scattered thunderstorm development late this afternoon through the evening has the potential to impact DRT/SAT/SSF but confidence is low in direct impacts for San Antonio, thus carrying VCTS there for now. Deteriorating flight conditions return tonight with IFR by 03z at AUS and MVFR at DRT/SAT/SSF by 03-05Z. SAT/SSF could see IFR as early as 09/12Z but confidence too low to include at this time. Somewhat better shower and thunderstorm coverage is expected late tonight near DRT and then by the afternoon hours Tuesday at the I-35 sites, details to be refined. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 62 73 61 69 59 / 40 90 70 60 20 Austin Bergstrom Intl Airport 63 75 61 69 58 / 40 80 70 60 20 New Braunfels Muni Airport 65 77 62 72 59 / 40 80 70 60 20 Burnet Muni Airport 59 71 57 66 57 / 50 90 50 50 20 Del Rio Intl Airport 69 81 66 75 63 / 40 60 50 60 30 Georgetown Muni Airport 61 72 59 67 57 / 50 90 60 50 20 Hondo Muni Airport 67 80 64 74 59 / 50 80 60 60 20 San Marcos Muni Airport 64 76 61 70 58 / 40 80 70 60 20 La Grange - Fayette Regional 69 81 64 72 61 / 40 70 80 70 20 San Antonio Intl Airport 66 78 63 71 61 / 40 80 70 60 20 Stinson Muni Airport 68 81 65 73 62 / 40 70 70 60 20 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Short-Term/Aviation...04 Long-Term...05 Decision Support...Platt
Area Forecast Discussion
National Weather Service Grand Junction CO
508 PM MDT Mon May 10 2021 .SHORT TERM...(Tonight through Tuesday night) Issued at 219 PM MDT Mon May 10 2021 The closed low responsible for our unsettled weather this afternoon remains over central Idaho at this hour. Flow around this low, along with an upper level jet streak, and cooler temperatures aloft have all combined to create a showery, and now stormy afternoon. The HRRR and NAMNest are the big winners this afternoon highlighting where convection has setup and tapped into instability aloft. CAPE values of around 500 J/kg north of I-70 have also aided in said convection. For now, just seeing rainfall amounts of .01 to .03 inches but expect under and near any storm cores that number will be a bit higher. Also wouldn`t be surprised if some of the stronger cells don`t bring some stronger winds to the surface. Meanwhile down south, plenty of breaks can be seen in the cloud cover which has allowed some deeper mixing to occur. Thanks to the jet streak aloft, a few wind gusts of 50 mph have been noted near Durango and Pagosa Springs this afternoon. Winds have subsided some but expect the breezy conditions to persist through sunset. Overnight, the NAMNEST is hinting at an uptick in precip for the San Juans as do other models, just not as much, so slightly upped pops for the region. Still looking for some light snow overnight in the 1 to 3 inch range for the higher terrain along the Divide and onto the Grand Mesa. Tomorrow, the midlevel circulation will have reached the Co/Wy border and continue moving eastward. Like today, the best instability and strongest CAPE (~300 J/kg) will be north of the I-70 corridor, closest to the disturbance where the best lift will be. Convection doesn`t look as widespread and looks to quickly shutdown heading into the evening hours. Down south, another breezy afternoon for the southern valleys. High temps will remain below climatological norms today and again tomorrow but a quick rebound will kick in Wednesday onwards. .LONG TERM...(Tuesday night through Sunday) Issued at 353 AM MDT Mon May 10 2021 A weak ridge begins to build in over the Desert Southwest on Wednesday. Afternoon highs will increase a few degrees each day, and, by the end of the week, are expected to be close to 10 degrees above normal for mid-May. Conditions will remain generally dry through the period. The next Pacific trough moves onshore Friday, and is forecast to deepen along the California coast through the weekend. Ensemble and deterministic models seem to be in pretty good agreement about the general progression of this system, even indicating the formation of a cut off low over northern California Saturday morning. As this trough continues to deepen, the pressure gradient over eastern Utah and western Colorado is expected to tighten up, leading to enhanced afternoon winds for Saturday and Sunday. The winds, combined with warm and dry conditions, may lead to potential critical fire weather conditions for the weekend. The low is currently forecast to move through the Four Corners region Sunday night into Monday, but confidence is low with this occurring at the end of the forecast period. The forecast is likely to change in the coming days as models move into better agreement. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 504 PM MDT Mon May 10 2021 Scattered showers and thunderstorms will persist at KVEL, KHDN, KEGE, KGUC and KASE over the course of the evening. These showers with produce gusty and erratic winds, but little in the way of rainfall. VFR conditons are expected, although MVFR may be possible with these showers. Shower activity will wind down and become focused along the divide overnight and into tomorrow. Another round of showers is expected in the central and northern mountains tomorrow afternoon. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...None. UT...None. && $$ SHORT TERM...TGR LONG TERM...BGB/MDA AVIATION...TGJT
Area Forecast Discussion
National Weather Service Wilmington NC
1021 PM EDT Mon May 10 2021 .SYNOPSIS... Scattered showers and thunderstorms will accompany a cold front tonight. The front will stall offshore Tuesday with unseasonably cool temperatures expected for the next few days. A soaking rain may develop Wednesday as a wave of low pressure passes by to our south. High pressure late in the week will lead to pleasant weather conditions. && .UPDATE... Based on radar and latest HRRR and NAMnest convective potential I`ve limited overnight shower and t-storm chances to areas along and north of the NC/SC state line, focused mainly across Robeson and Bladen counties where convection currently near Charlotte and Albemarle move over the next few hours. Across much of northeastern South Carolina away from the state line it appears too much dry air exists to allow convection to form when the front arrives. All other changes to the forecast were minor. && .NEAR TERM /THROUGH TUESDAY NIGHT/... Active weather period over the next 36 hours with strong to severe thunderstorms expected and a good shot of cooler air heading toward the region. The forecast area currently is positioned in the warm moist sector in front of an incoming cold front. Temperatures across the region range from 85 at Wilmington to 73 at Hartsville with dew points in the upper 50s to low 60s. This air mass in combination with instability aloft with decent speed shear values will support the possibility of severe thunderstorm development. Large hail, damaging winds, and an isolated tornado are all possible. Based on the latest satellite imagery and high resolution model guidance, storms should develop by mid to late afternoon and continue through the late evening through early overnight hours. Anywhere from 0.25 to 0.50 inches possible with higher amounts in the strongest developing thunderstorms. The cold front should pass by Tuesday morning and start a cooling trend with afternoon highs Tuesday between 10 and 20 degrees cooler than today in the upper 60s to mid 70s. Some chances for light precipitation will continue along and behind the front through the day Tuesday, although chances for severe weather is not anticipated Tuesday. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... Cold and wet day for Wed with northerly winds and continued CAA as high pressure builds down from the Upper Midwest and cold front lingers to the south. Increasing isentropic lift as a wave of low pressure moves along lingering front to the south will produce some decent rain across the Carolinas, mainly through SC Wed aftn. The latest guidance shows max temps in the early morning just below 60 and then remaining near steady or possibly dropping through the day with temps in the mid to upper 50s for much of Wednesday daytime hours. This could lead to record low maximums for the day. The lowest max temp for ILM on Wed the 12th is 65, LBT is 65, MYR is 65 and FLO is 67. Wave of low pressure will track off to the E-NE late Wed as high pressure builds down from the north. Heavier rain should taper off, with soundings showing some drier air moving in, but looks like clouds and light rain or drizzle will hang on into Thurs across the area. NAM soundings keep a saturated column into Thurs with a steep inversion holding on to shallow colder air into Thurs. For now, will keep chc of rain across much of the area into Thurs as another wave of low pressure moves by to the south and shortwave digs down from the north. Overall, cloudy and cool and wet weather through the period with overnight lows dropping below 50 Wed night inland and rebounding into the 60s on Thurs. && .LONG TERM /FRIDAY THROUGH MONDAY/... Mid to upper trough running down from the Great Lakes will track east and any shortwave energy will lift north. High pressure extending down from the north will migrate eastward and offshore through the weekend. Overall, expect clearing on Fri and dry weather with NE winds veering around to onshore and eventually southerly into early next week. May see some clouds increase Sun into Mon as warmer, more moist air moves northward. Temps well below normal on Thurs but plenty of sunshine over the weekend will help temps rebound as air mass modifies slowly with a return to normal by early next week. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... A cold front extending across central North Carolina should drop south and across our area between 04-07z Tuesday. Scattered showers moving across MYR early this evening are ahead of the front, while we`ll be watching a broken line of convection and possible t-storms just ahead the front itself that may impact LBT and ILM mainly between 02-05z. Behind the front, low clouds will spread in from the north and northeast and blanket the area through a good portion of Tuesday. IFR conditions appear likely to develop early Tuesday morning in the 07-12z timeframe and may not lift above 1000 feet (MVFR) until afternoon at some airports. Extended Outlook...The cold front will stall offshore Tuesday. A developing wave of low pressure will spread rain and low clouds across the area late Tuesday night into Wednesday with MVFR to IFR ceilings expected. Conditions should improve Thursday. && .MARINE... Through Tuesday night...Seas 4 to 6 feet with winds 15 to 20 kts gusting to 25 kts should continue through the early evening with small craft advisory concerns ending by the late evening. High risk for rip currents continue as strong southerly waves around 7 seconds will impact south facing beaches. Seas become 2 to 3 feet through the night into Tuesday with windspeeds generally at or below 15 kts. Main concern for sailing vessels is the sharp wind shift that will occur as cold front approaches and winds shift from the southwest to the north/northeast. Wednesday through Friday...Persistent NE winds will continue with cold front stalled just south and high pressure building in from the north will produce a sustained period of SCA conditions possible Wed to Fri with unseasonably cold air running over the waters Wed into Thurs. Wave of low pressure along the front will also help to enhance the winds and produce unsettled weather through mid week. Shortwave will finally lift off the the northeast on Fri as sfc high to the north migrates east and offshore into the weekend. NE winds will veer around slowly into the weekend. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ SYNOPSIS...DCH UPDATE...TRA NEAR TERM...MCK SHORT TERM... LONG TERM... AVIATION...TRA MARINE...MCK/RGZ
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
615 PM CDT Mon May 10 2021 .SHORT TERM... 258 PM CDT Through Tuesday night... Similar to much of May so far, the primary forecast items of interest are low temperatures and potential for frost, which both of these next two nights present for at least parts of the area. Scattered showers developed early this afternoon in a broad frontal convergence zone located along and about 60 miles south of I-80. These showers have focused on the southern end of the frontal zone, where there has been a few pulses of intra-cloud lightning but otherwise fairly subdued. It looks like there is continuing suppression further north behind the morning short wave, which scooted along a little quicker than earlier thought. That has limited any convective showers in the I-80 corridor area. Steep low-level lapse rates and 0-3 km CAPE of 100 J/kg are analyzed near I-80 and just south by the SPC RAP mesoanalysis, where there is clearing and clumped cumulus. If some of that can develop a little more as the suppression eases, there may still be a few gustier showers in that area that shift southeast, but confidence is not that high given observational trends. Further north, a few showers are possible away from the lake shadow (where there are cooler temperatures from the lake) due to cold mid-level temps (500 mb of -24C) and surface heating. For this evening, some showers may have a propensity to fester in the far south with the slow movement of the surface boundary and the continued passage of an elongated, sheared short wave in the mid-levels. These should work their way south of the area and/or dissipate by midnight. The north edge of low to mid cloud will be slower to depart based on observational trends in the region and guidance moisture progs. A north-to-south clearing is expected but the rate in which that clearing occurs is uncertain. Northern locations naturally have a higher confidence, and this is where minimum temperatures in the mid 30s to pockets of lower 30s in outlying areas are forecast. For this reason, a Frost Advisory has been hoisted for these northern locations. For the I-80 corridor, including far northwest Indiana, these locations are more marginal for areas to widespread frost. Also far northwest Indiana looks to have a light wind flow off the warmer lake. So no Advisory at this time and the evening shift will further assess. Tuesday should be a day without any precipitation, and it`s been a little while since that (for instance, Rockford has had seven straight days with at least a trace of precip). Canadian high pressure of 1032 mb will gradually sprawls its way southward from the Upper Midwest during the day, resulting in an early wind uptick off the lake. With 850 mb temperatures being below 0C for one more day, highs look to only peak in the 50s to 60 far west, with again upper 40s near the lake. For Tuesday evening, conditions are ideal for maximized radiational cooling and temperatures below those forecast tonight. Future shifts will assess the likely need for a headline, and it is possible some of the area will require a freeze headline. MTF && .LONG TERM... 258 PM CDT Wednesday through Monday... It appears that Wednesday night into early Thursday will be the last frosty night/early morning outside of Chicago in this unusually cool stretch. North to northeast winds will be in place again for Wednesday pushing lake cooled air across much of the immediate Chicago metro and into northwest Indiana. This will keep highs in the lower to mid 50s for these areas while the remainder of the area sees low to mid 60s for highs. Dew points away from the lake in the upper 20s to lower 30s at peak heating, followed by light winds and clear skies under the surface high at night should set the stage for good radiational cooling. Have areas of frost mention in the interior Chicago suburbs and points inland, and could envision needing another frost advisory for some of our counties, with forecast lows in cool spots down to the mid 30s, with isolated low 30s possible far north where it`s been driest and given the favorable radiational setup. The surface high will be shifting east Thursday suggesting more of a southerly component to the wind, albeit with light speeds, but potentially reducing the inland extent of lake cooling with more of a southeast direction off the lake. However, speeds will likely be light enough to allow a traditional lake breeze to develop anyways. Guidance is also in good agreement on an upper trough axis pivoting across the region but precipitation prospects are quite low with this given a dry airmass being in place. Another trough axis is forecast to move through later Friday, though the dry surface high influence and dry antecedent air mass appears favored to hold back precip chances until during the weekend. Despite increasing mid clouds, nice air mass modification will bring upper 60s to around 70 inland on Friday, while lakeshore areas are limited to the upper 50s-lower 60s by afternoon lake breeze push. An unsettled upper pattern continues Saturday with better (but still officially low-mid chance) shower chances on Saturday and especially Sunday as more earnest warm advection arrives. Instability progs are pretty meager, as well as mid-level lapse rates, so kept slight chance thunder mention limited to Sunday PM. Warming air mass aloft with increased cloud cover could keep max temps in the upper 60s-lower 70s range through the weekend, while still maintaining lakeside cooling from onshore wind component into at least IL shore. Expect highs in the 70s inland by Sunday. The upper ridge looks to crest the area Monday bringing even warmer air (mid 70s away from IL shore) with it but shower/thunder chances continue. MDB/Castro && .AVIATION... For the 00Z TAFs... Aviation Forecast Highlights: * Northeast surface winds through the period, generally 10-15 kt during daytime hours. * Dry with VFR conditions through the period. Diffuse surface cold front and weak low pressure reflection has settled south of the terminals this afternoon, with showers and a few thunderstorms to dissipate early this evening while remaining well south. A mid-level trough rotating southeast through the western Great Lakes region will maintain some VFR SCT-BKN cloud cover into the overnight hours, with bases generally in the 6000-8000 foot range. Once this mid-level disturbance moves off to the east of the area Tuesday morning, surface high pressure will build southeast from the upper Mississippi Valley into northeast IL and WI through Tuesday evening. This will maintain northeast surface winds of generally 10-15 kts during the day, before becoming somewhat light and variable Tuesday night in the vicinity of the surface high pressure center. Ratzer && .LOT WATCHES/WARNINGS/ADVISORIES... IL...Frost Advisory...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ011- ILZ012-ILZ013-ILZ103...1 AM Tuesday to 8 AM Tuesday. IN...None. LM...None. && $$ Visit us at Follow us on Facebook, Twitter, and YouTube at:
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
856 PM EDT Mon May 10 2021 .SYNOPSIS... A reinforcing cold front will cross the region Tuesday. High pressure will build toward the region Wednesday, with the high building overhead during latter portion of the week. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... It is currently clear to partly cloudy, but clouds will be on the increase overnight as a weak disturbance embedded in zonal flow passes through. The HRRR even hints that a few light showers may try to form across southwestern portions of the forecast area. If any showers were to form, they`d be light and brief in nature, so nudged POPs down below slight chance. Cloud cover will keep temperatures warmer than they potentially could be, with overnight lows ranging from the upper 30s in the mountains, to around 50 in downtown DC and Baltimore. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... A mid-upper level trough currently centered over Lake Superior will slowly drift southward toward our area during the day tomorrow. This will drive a surface cold front southeastward toward us. As the upper low drops southward, mid-levels start to cool, and the surface cold front starts to cross the region, showers are expected to develop in response to daytime heating tomorrow afternoon. With equilibrium levels around -10 C, no lightning is expected, but the showers could produce a brief heavy downpour with gusty winds. While daylight heating loss will cause showers to dwindle after dark, some may linger especially over southern Maryland as the trough and front will continue to act as forcing. Temperatures will be quite chilly tomorrow night, with lows dropping into the 30s (to the west of the Blue Ridge) and lower to middle 40s (to the east of the Blue Ridge). A Freeze Watch remains in effect for most of the Allegheny Front where temperatures are likely to be coldest. Zonal flow aloft will be maintained on Wednesday as the upper low to our north starts to move off to the east. At the surface, high pressure will build toward the area from the Great Lakes. The combination of building high pressure and zonal flow aloft will lead to mostly sunny skies. Temperatures will hold below normal (highs in the 60s) as northwesterly winds in advance of the approaching high continue to transport seasonably cool air into the area. As high pressure builds closer still Wednesday night, wind may go weak enough for some spots to decouple. As a result, frost/freeze headlines may potentially be needed again to the west of the Blue Ridge. && .LONG TERM /THURSDAY THROUGH MONDAY/... Cyclonic flow begins to exit the northeastern U.S. on Thursday with a split jet structure noted further upstream. A sprawling ridge of surface high pressure extends from the Missouri Valley into much of the eastern U.S. While a passing shortwave trough will weaken this dome of high pressure, it should remain a fixture in the forecast into the upcoming weekend. Models are in agreement that height falls should move through the Mid- Atlantic on Friday. Compared to this past weekend`s upper low, this should be much less impressive in terms of shower production. The vertical column is not nearly as cold, instability is nearly non-existent, and wind fields aloft are quite weak. However, will maintain a chance of some showers for Friday. This system eventually induces cyclogenesis well off the southeastern U.S. coast which is of no consequence to the Mid- Atlantic region. For the weekend, the northern stream is forecast to dominate the pattern with prevailing northwesterly flow expected. This will maintain the extended period of below average temperatures. Depending on the level of amplification of the upstream flow, some shower chances may intermittently impact the region over the weekend. Confidence does remain low in the threat for showers. Winds eventually become westerly by Sunday which may bring temperatures closer to mid-May climatology. This would favor mid 70s with 60s across the higher terrain. Will continue to monitor the progression of an approaching warm front which may aid in further warmth into next week. The composite of global ensembles support a warming trend which also is indicated in the Day 6-10 Climate Prediction Center outlook. && .AVIATION /01Z TUESDAY THROUGH SATURDAY/... VFR conditions and northwesterly winds are expected to predominate at the terminals through Wednesday. Winds may gust to around 15 to 20 knots at times. While no restrictions are likely, a brief shower Tuesday afternoon as a cold front passes could cause a brief reduction in vsby. Thursday and Friday should bring VFR conditions to the terminals. With surface high pressure in place, winds are to be on the lighter side with variable directions at times. A few showers are possible by Friday, but confidence is below average. && .MARINE... Winds will remain northwesterly through Wednesday, with gusts to low-end SCA levels at times. The only opportunity for winds to get stronger than low-end SCA will be tomorrow afternoon in any convective showers that form. Coverage of these showers isn`t expected to be high, but an SMW or two can`t be ruled out tomorrow afternoon if these showers are able to bring higher winds down from aloft. Sprawling high pressure across the area will keep winds below small craft levels for Thursday and Friday, and likely into the weekend as well. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...Freeze Watch from late Tuesday night through Wednesday morning for MDZ001. VA...Freeze Watch from late Tuesday night through Wednesday morning for VAZ503. WV...Freeze Watch from late Tuesday night through Wednesday morning for WVZ501-505. MARINE...Small Craft Advisory until 6 AM EDT Tuesday for ANZ531-532-539- 540. Small Craft Advisory from 4 PM Tuesday to 6 AM EDT Wednesday for ANZ530>534-536>541-543. Small Craft Advisory from midnight Tuesday night to 6 AM EDT Wednesday for ANZ542. Small Craft Advisory until 10 AM EDT Tuesday for ANZ533-534- 537-541-543. Small Craft Advisory from midnight tonight to 6 AM EDT Tuesday for ANZ530. Small Craft Advisory from 4 PM Tuesday to midnight EDT Tuesday night for ANZ535. && $$ SYNOPSIS...KJP/RCM NEAR TERM...KJP/RCM SHORT TERM...RCM/KJP/RCM LONG TERM...BRO AVIATION...BRO/KJP/RCM MARINE...BRO/KJP
Area Forecast Discussion
National Weather Service Midland/Odessa TX
646 PM CDT Mon May 10 2021 .DISCUSSION... See 00Z aviation discussion below. && .AVIATION... MVFR CIGs will return to MAF/HOB/INK/FST in the next few hours and should drop to IFR after 06Z at HOB and MAF. Have kept CIGs IFR at HOB/MAF until around 18Z when they scatter out of all terminals but they may lift to MVFR for several hours prior to this. SHRA and TS will develop around 12Z and while it is expected to remain just east of the terminals, it could impact MAF and FST. Confidence is too low to include in those TAFs at this time. Hennig && .PREV DISCUSSION... /issued 245 PM CDT Mon May 10 2021/ DISCUSSION... Vis satellite imagery and surface observations show morning stratus east of the Pecos is slow to erode this afternoon, aided by a steady NE PBL flow. A cold front extended from near KCNM-KPEQ-KOZA, w/the dryline banked up against the higher terrain, putting the triple point invof KCNM. In the bigger picture, WV imagery shows an upper trough crossing the Gulf of CA at 18Z, and is due into West Texas and Southeast New Mexico late tonight/Tuesday. Ahead of this, mesoanalysis shows a tongue of 4000 J/kg nosing into Terrell County in the warm sector, where 70+ dewpoints are creeping up the Rio Grande valley. Visible imagery shows a cu field already going up down there, w/the HRRR suggesting initiation around 20Z. Mesoanalysis shows mid-lvl lapse rates in excess of 7 C/km in the warm sector, so a large hail threat will be in play. Later tonight, convection is forecast to develop north and west on a strengthening LLJ, as easterly sfc flow surges moisture west. Lapse rates are forecast to moderate somewhat, but still pose a marginally severe hail threat. Ensembles depict PWATs of 2-3 devs above normal for the eastern zones, so a potential heavy rain threat will exist as well. Tuesday, the dryline, already banked up against the higher terrain, will mix very little east, and then surge west Tuesday night, w/50F dewpoints as far in as KATS/KCNM. A backdoor cold front will move SW through the Permian Basin Tuesday afternoon, and to the Presidio Valley late Tuesday night. This will collide w/the aforementioned Gulf of CA trough, expanding the convective threat west. Best deep-lyr shear and instability will be in the better moisture eastern zones, maintaining a severe threat there. Post-frontal temps Wednesday will remain below 70F across the lowlands, w/cool NE flow keeping stratus socked up against the higher terrain. Chances of convection will taper off to the east be Wednesday evening. Weak ridging develops into the area Thursday, for a gradual warmup to around normal by Sunday/Monday. Convection will be possible Thu-Sat as perturbations move through the ridge, mainly west, but this activity looks isolated for the most part. FIRE WEATHER... A Fire Danger Statement is out today for elevated fire conditions across the Sacramento, Delaware, and Guadalupe Mountains as well as Culberson county. RFTI values of 4 to 5 and RH as low as 7% will be present. Fair to good overnight recovery is expected out there, although relative humidity will drop down to critical levels again on Tuesday. Another Fire Danger Statement may be needed. Storms are expected to develop S of the Pecos tonight before moving northeast through the region Tuesday morning. Gusty and erratic winds may be possible with any of these storms, along with frequent lightning. These storms look to produce some locally heavy rainfall, which may tamper fire weather concerns for the foreseeable future. A cold front moving through the area will cool temperatures through Thursday to well below normal. && .PRELIMINARY POINT TEMPS/POPS... Big Spring 54 69 51 61 / 30 30 30 40 Carlsbad 56 83 51 65 / 10 0 40 20 Dryden 66 86 61 70 / 20 20 40 50 Fort Stockton 61 85 54 65 / 10 10 40 40 Guadalupe Pass 57 78 49 62 / 10 0 20 20 Hobbs 53 73 48 61 / 10 10 30 30 Marfa 53 85 50 70 / 10 0 20 20 Midland Intl Airport 56 76 51 62 / 30 20 40 40 Odessa 56 76 51 62 / 20 10 40 40 Wink 59 83 53 66 / 10 10 40 30 && .MAF WATCHES/WARNINGS/ADVISORIES... NM...None. TX...None. && $$ 99/99/10
Area Forecast Discussion
National Weather Service Shreveport LA
1011 PM CDT Mon May 10 2021 .UPDATE.../Tonight/ Convective evolution continues to be tricky to forecast, and hi- res rapid update models haven`t been much help this evening. The latest HRRR does seem to be initializing better this run, and the 12Z Euro is not too far off on placement of QPF thus far. If these models have any handle on what will happen during the overnight, convection should stay mostly confined to our nern half, generally from around Tyler to Shreveport to Jena and points newd. have increased PoPs across these areas for the overnight pd. Otherwise, have made some minor tweaks to temps based on current obs, which were running a few degrees cooler than previously fcst for the central portions of the region. Otherwise, fcst is reasonably on track this evening. /12/ && .PREV DISCUSSION... /issued 706 PM CDT Mon May 10 2021/ AVIATION... There is much uncertainty with regard to convective coverage/location this TAF pd. Have tailored TAFs to reflect ongoing radar trends, but the picture becomes less clear for the overnight through Tuesday. Safe to say that we will see multiple rounds of tstms through the pd, which could impact any site in the area. Otherwise, expect mostly IFR conditions to persist through the pd. /12/ && PREV DISCUSSION... /issued 331 PM CDT Mon May 10 2021/ SHORT TERM.../Tonight through Tuesday Night/ Sct svr elevated convection continues to build SE into extreme NW LA attm, riding along an area of higher MUCapes of 1000-2000 J/Kg coinciding with the lingering H850 trough over the Red River Valley of Srn OK/N TX into the Nrn sections of SW AR, where steep lapse rates persist ahead of weak perturbations in the nearly zonal flow. The 12Z CAMs, which somewhat initialized on this convection this AM, suggest that it will weaken late this afternoon/early evening, although additional convection redevelopment is expected later this evening and overnight across NE TX/SE OK/SW AR/possibly extreme Nrn LA, with the approach of another perturbation in the flow that will interact with increasing convergence along the H925 trough as it begins to lift back N across E TX/NW LA into SW AR. Thus, have stair-stepped pops back from chance to likely across E TX/SW AR by late evening, before likely expanding pops farther E across the remainder of SW AR overnight. Fortunately, these areas will be able to take the rain tonight, with the weak cold front now over the Srn sections of NCntrl LA into Deep E TX now expected to be much of a player tonight as it should seep just S of the area this evening. While there may be a brief lull in the extent of convection Tuesday morning, weak sfc low development along the lingering sfc frontal bndry just to our S may result in the bndry nudging back N a tad into Deep E TX and Cntrl LA from the late morning and a portion of the afternoon. This will occur as the upper trough now swinging through the Great Basin into the Rockies ejects into the Plains and dampens Tuesday, although this trough will advect Pacific moisture NE ahead of the Baja upper trough and become absorbed into the Nrn stream trough into the Srn Plains/Lower MS Valley Tuesday. This will set the stage for convection becoming more numerous by late morning and especially for the afternoon areawide. While the setup is not typical for the transitional heavy rainfall events, am concerned though of the proximity of the sfc bndry to our S over areas that remain saturated in wake of widespread heavy rainfall (3-7+ inches) and flooding that occurred Sunday afternoon/evening over Deep E TX/WCntrl LA. Have deferred a Flash Flood Watch for this area for the graveyard shift later tonight, with the greatest threat for moderate to potentially heavy rainfall over this area likely being late Tuesday morning through Wednesday afternoon. Confidence is high though such that pops have been increased to high end categorical areawide Tuesday afternoon, before mid and upper level drier air begins to entrain SE into NE TX/SE OK/SW AR Tuesday night. Thus, rain rates will begin to taper off from NW to SE Tuesday night as the aforementioned trough axis moves through the Srn Plains into the Lower MS Valley. Did continue to undercut the NBM max temps over much of the area Tuesday, as little warming will occur over the cool sector with the increasing convection. 15 LONG TERM.../Wednesday through Monday Night/ By Wednesday, showers and thunderstorms will be ongoing along a stalled 850mb front. With moderate to heavy rainfall expected previous to this, some flooding issues could remain during this time. However, by Wednesday afternoon, another trough will move through the midwest. This will push the 850mb front through the region, and rain chances will diminish from north to south. Northwest flow will bring in drier weather for Thursday along with slightly below normal temps. Look for this dry weather to continue on Friday and Saturday as upper ridging builds into the region, but a slight warm-up in temperatures will start during this period and continue through early next week. The ridge starts to break down late into the weekend and the flow will become more zonal. Rain chances will return for Sunday and the first part of next week as disturbances move across the region along the flow. /20/ && .PRELIMINARY POINT TEMPS/POPS... SHV 55 65 57 67 / 70 90 90 50 MLU 58 67 59 68 / 60 90 90 60 DEQ 53 59 52 67 / 70 90 60 20 TXK 54 59 53 67 / 70 90 80 30 ELD 53 62 53 68 / 70 90 80 40 TYR 57 64 56 68 / 70 90 80 40 GGG 54 64 56 66 / 70 90 90 40 LFK 67 78 62 68 / 50 90 90 60 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...None. TX...None. && $$ 12/15/20