Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/02/21

Area Forecast Discussion
National Weather Service Binghamton NY
830 PM EDT Tue Jun 1 2021 .SYNOPSIS... Dry quiet weather is expected through tonight. Rain and a few thunderstorms are possible Wednesday and Wednesday night. Another round of showers and storms are possible on Thursday into Friday before hot and humid conditions settle in for the weekend and early next week. && .NEAR TERM /THROUGH WEDNESDAY NIGHT/... 815 pm update... A few targets of opportunity and changes were made to the near term forecast grids with this update: Clouds are mainly high cirrus across CNY, and with dew points coming in lower than expected (42-47F) dropped tonight`s lows across most of CNY by a few degrees. Forecasting lows in the mid-40s to lower 50s...except low to mid-50s for NE PA, where the clouds are expected to be more extensive and thicker. Made some adjustments to slow the timing of clouds, showers and t`storms moving north on Wednesday based on the latest hi-res model data; HRRR, RAP and NAM-3km. Forecast is still basically on track for Wednesday, but am expecting a few breaks of sun in the morning from the Twin Tiers north into CNY, with showers arriving late morning to midday for NE PA...and not until mid to late afternoon for much of CNY. POT Thunder chances looked good; and continued to cap this potential at slight chance. Bumped tomorrow`s Max Ts up a few degrees, considering the later arrival of steadier very close to the latest blended (NBM) guidance. This gives low to mid-70s for most locations, with upper 70s from Syracuse east to Utica/Rome. Latest guidance is not as wet Wednesday night for much of our forecast area. The initial warm front and associated precip will be lifting north in the evening. Then, behind this feature there should be a lull, with just some isolated to scattered showers activity. The exception will be across the far west (steuben to yates and Seneca counties) where a band of rain and embedded t`storms may continue, associated with a low pressure system slowly moving east across Lower Michigan. Another batch of rain showers and perhaps elevated t`storms may also surge north along from the Mid-Atlantic and southern PA during the predawn hours Thursday...overall the shower chances will increase for much of the CWA heading toward daybreak Thursday. A bit more humid and mild, with lows in the 50s to near 60. QPF amounts remain largely unchanged through Wednesday night. With basin averages of mainly 1/4 to 1/2 inch expected...there will be some narrow stripes with locally higher amounts. 330 pm update... Main concerns in the near term are focused on the next round of rain showers and even a few weak thunderstorms Wednesday into Wed night...along with warming temperatures and increasing humidity. Current synoptic setup across the region this afternoon places a weak surface high over the wrn Great Lakes into the Northeast and a nearly zonal flow aloft behind the departing s/w to the east, but with heights aloft gradually rising. The trend of rising heights will continue into tonight as a longwave trough deepens over the central US and downstream ridging amplifies across the Northeast. A steady southwest flow will develop from the Ohio Valley into the mid Atlantic region as a warmer and more humid air mass moves in from the south associated with a lifting warm front. Temperatures this afternoon have warmed nicely into the upper 60s to mid/upper 70s in some locations. Cloud cover will increase later this evening which will keep the warm air in place near the surface and only allow temperatures to cool into the lower to mid 50s. The air mass will be relatively dry initially early Wed morning, but strong/deep moisture advection will quickly occur through the rest of the morning and combine with an upper level short wave moving in from the southwest and weak isentropic lift across VA and southern PA. The forcing and moisture will generate a blossoming area of rain showers that will fill in north to south Wed morning. This area of precip may actually become more scattered in nature by the early afternoon as some of the drier air mixes in. However, a continuous supply of moisture from the southwest will create favorable conditions for a second surge of widespread showers into the evening and overnight hours. There will also be the potential for a few isolated weak thunderstorms Wed afternoon and into the night. ML CAPE values during the day Wed will be on the low end of the spectrum...only 100 J/kg or so with around 30 kt of deep layer shear...with most of the convection rooted in the boundary layer. The main threats will be gusty winds and small hail. Going into the evening, surface temperatures cool and a weak inversion forms just above the deck. This will allow the convection to become elevated and therefore inhibit the threat for hail or wind. Will need to monitor the potential for localized flash flooding late Wed and Wed night. Model sounding hodographs are fairly unidirectional and there is a deep saturated layer throughout most of the column. There could be a chance of some storms training and producing efficient and brief/heavy rainfall rates. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... 300 PM Update... The short term starts with a slight threat for some severe weather across southern portions of Northeast PA on Thursday. 0-6 km shear is forecasted to be around 50 kts though most guidance has MUCAPE less than a 1000 J/kg, with thick cloud cover limiting heating. Some isolated high wind gust would be possible but the threat is very marginal for our region. A bigger threat will be heavy rain. PWATs are approaching 1.5 to 1.75 inches along with warm cloud depths greater than 10K along with skinny CAPE. Thunderstorm motions are expected to be fairly fast at around 30 mph but training of thunderstorms is possible. Highest PWATs are still off to our east and will continued to be monitored for any westward shifts. A few showers and thunderstorms make it into Thursday night as a mid level trough moves in and colder temperatures moving in aloft keeps some instability through the overnight hours. Shear decreases quickly as the trough moves overhead so severe weather is not expected to continue into the overnight hours. Afternoon thunderstorms are possible on Friday once again but with a more stable air mass moving in, coverage will not be as widespread with any showers and thunderstorms dissipating in the early evening with the loss of daytime heating. && .LONG TERM /SATURDAY THROUGH TUESDAY/... 300 PM Update... The long term is looking very warm for most of the Northeast. A strong upper level ridge builds in with 500 mb height anomalies approaching 3 standard deviations above normal by the weekend. This results in widespread daytime highs in the mid to upper 80s this weekend and then getting into the upper 80s and low 90s by early next week. These highs may even need to be bumped up higher as we get later in the week given that models were too low with the high temperatures during the warmer weather that we saw last week. Dew points also look to be on the increase late this week into early next week with mid to upper 60s possible. Even though high pressure is in place, enough afternoon instability will be around for a few isolated thunderstorms to develop in the late afternoon across higher terrain like the Catskills and Pocono Mountains. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... VFR through most of the TAF period with winds under 10 knots. However, ceilings should form and lower throughout the afternoon to low end VFR and even some occasional MVFR ceiling levels. This will be associated with some showers moving south to north during the mid and late afternoon hours. These may have some thunder and cause visibility restrictions but the confidence in any convection is low with limited coverage. As a result, only tempo groups for MVFR showers were included at this time. Outlook... Wednesday Night...Occasional restrictions possible in scattered showers and possibly a thunderstorm. Thursday...Widespread rain showers and a chance of thunderstorms with associated restrictions. Friday...Restrictions possible in showers and storms. Saturday and Sunday...Mainly VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && $$ SYNOPSIS...BJT NEAR TERM...BJT/MJM SHORT TERM...AJG LONG TERM...AJG AVIATION...MWG
Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
811 PM CDT Tue Jun 1 2021 .DISCUSSION...Updated for latest aviation discussion below. && .AVIATION...As the conv fades to the south of the RGV, it`s leaving behind a mix of VFR/MVFR conditions for the Valley airports. Both the HRRR and the RAP13 models are insisting on redeveloping some conv just south of the Rio Grande over Tamaulipas State in Mexico. Both of these models do not to be initializing very well at this time, but generally keep the RGV rainfree throughout the night. Some weak 500 mb vorticies will eject out of the closed 500 mb Baja Low tomorrow to possibly spark off some conv later in the morning and into the afternoon/evening hours. So will include some PROB30 groups later in the TAF period for both HRL and MFE. Overall aviation conditions will depend heavily on the very short range conv trends, so aviation forecast confidence is only so-so this evening. && .PREV DISCUSSION... /issued 241 PM CDT Tue Jun 1 2021/ SHORT TERM (Now through Wednesday Night): A cluster of thunderstorms moved through portions of the CWA this morning. The storms resulted in mainly nuisance flooding in the mid-valley area. Conditions have quieted down, but the HRRR maintains isolated convection around the area through the day, with some better defined moderate activity possible this evening. The BRO CWA remains in an SPC general thunderstorm convective outlook area through tonight. A mid level low is positioned over Baja California, and disturbances have been making their way east across Mexico to help trigger storms upstream which then move into and through the CWA. Precipitable water was a decent 1.75 inches at BRO this morning, and a moderate southeast wind will keep the moisture coming in off the Gulf. Thus the NAM, for example, shows isolated to scattered convection on Wednesday as well. SPC has a portion of the CWA, the northwest corner, in a marginal severe thunderstorm convective outlook area for Wednesday, with the remainder of the BRO CWA in a general thunderstorms outlook area. The mid level low will start to move east after the short term, with higher pop chances later in the week. Feel that the model consensus may be broad-brushing pops a bit, with short term guidance a little more conservative, but it seems clear that unsettled conditions will continue, with areas and times of more focused activity. Overnight low temperatures will hold near normal with Wednesday high temps near normal east and slightly below normal west, especially where rainshowers persist during the day. LONG TERM (Thursday through Tuesday): Although exact details are still being ironed out, confidence continues to increase on a very wet pattern and abnormally cool temperatures across Deep South Texas through at least this upcoming weekend. Atmospheric conditions will dry out and temperatures will warm up to near or slightly above seasonal average by the start of next week. Closed 500mb low over Baja California will finally drift eastward over northern Mexico beginning Thursday afternoon as a positively-tilted longwave trough swings over the Ohio Valley. The positive tilt of the trough will be able to absorb and pull the Baja low eastward toward Texas before closing off again as it drifts over the state. A plethora of low-level moisture, plenty of instability, and modest to strong lifting downstream of the trough axis will cause scattered to numerous showers and thunderstorms, potentially strong-severe and heavy thunderstorms at times. Very heavy rainfall is a possibility, especially on Thursday and Friday, as PWATs across Deep South Texas are forecast to increase to or above 2.0 inches. WPC has included all of Deep South Texas in a Marginal Risk of rainfall exceeding flash flood guidance in their D3 (Thursday) Excessive Rainfall Outlook. At this time, a Flash Flood Watch has not been considered, but that may change over the next 24 to 36 hours. Medium-range forecast models are in very good agreement that the mid-level low will slow down and stall over central Texas Friday afternoon/evening or by Saturday as a blocking pattern sets up. And even though the best lifting and dynamics will be north and east of the region this weekend, isolated to scattered showers and thunderstorms will remain possible on both Saturday and Sunday as the mid/upper low sits over the state. Strengthening subtropical ridging over southern Baja California will gradually push the low northward as the ridge drifts over northwestern Mexico beginning Monday. The influence of the ridge will nose over southern Texas and help warm temperatures up and dry the mid-levels out for the start of next week. Nevertheless, will leave in a slight chance of spotty showers for both Monday and Tuesday as low-level moisture remains abundant. Rainfall totals between Thursday and Sunday are still being fine- tuned at this time, but early indications show general amounts anywhere from one to three inches across the CWFA, with locally heavier amounts in some places. Once again, will likely make a decision on issuing a Flash Flood Watch in the next 24 to 36 hours. MARINE (Now through Wednesday Night)...Broad high pressure will support light to moderate southeast winds and low to moderate seas through the period. Isolated to scattered showers and thunderstorms will be possible from time to time. Thursday through Monday...Favorable marine conditions will prevail through a majority of the period courtesy of weak high pressure over the western Gulf of Mexico. Increasing winds and building seas will then occur beginning Sunday and continue into Monday due to an intensifying pressure gradient, resulting in Small Craft Exercise Caution and/or Small Craft Advisory along the Lower Texas Coast. && .PRELIMINARY POINT TEMPS/POPS... BAYVIEW/PORT ISABEL 76 87 75 87 / 10 20 30 50 BROWNSVILLE 76 89 76 87 / 10 20 30 40 HARLINGEN 75 89 74 87 / 10 30 40 50 MCALLEN 74 90 74 88 / 30 50 50 60 RIO GRANDE CITY 73 90 72 89 / 50 50 60 60 SOUTH PADRE ISLAND 78 82 77 81 / 10 20 30 40 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ This product is also available on the web at: HTTP://WEATHER.GOV/RGV Short Term/Aviation...60-Speece Long Term/Upper Air...55-Adams
Area Forecast Discussion
National Weather Service Columbia SC
745 PM EDT Tue Jun 1 2021 .SYNOPSIS... With southeasterly low level flow associated with a pressure ridge offshore pressure ridge offshore increasing, scattered showers and a few thunderstorms will develop across the region Wednesday especially in the east Midlands. Moisture is expected to increase through late week as an upper trough approaches from the west. A frontal system may move into the area over the weekend. This will result in a higher chance of showers and thunderstorms Thursday into the Weekend. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... Satellite imagery shows southeasterly winds pushing moisture and clouds inland from the coast with some cloud cover diminishing with sunset. Overnight expect mostly to partly cloudy skies as southeasterly flow continues pushing moisture into the area and pwat values around sunrise to 1.25 inches. A few showers will be possible toward daybreak in the eastern Midlands however with weak dynamics and dry air near the surface to be overcome QPF amounts will be a couple hundredths or less. With the clouds overnight low temperatures will be in the low to mid 60. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... Wednesday and Wednesday night...Strong surface pressure ridge centered off the coast of the Mid Atlantic region. Southeast low level flow/moisture flux increasing across the eastern Carolinas through the day with a weak warm front setting up near the area along with relatively high theta-e air in the east Midlands. It appears there will be a sharp moisture gradient though across the western Midlands and CSRA with precipitable water ranging from 1.15 in the Piedmont to greater than 1.5 inches in the east Midlands and coastal plain. Increasing southwest flow aloft late in the day with amplified upper trough well to the west from the Upper Midwest to the eastern Plains. Possible weak short wave in southwest flow aloft moving through the Upstate with isentropic lift/surface convergence focused in the central and east CWA. Raised pops in the east based on the increase in mos consensus pops. Temperatures may be a tad cooler tomorrow due to showers and noticeable spread in guidance. Instability appears weak but a few embedded thunderstorms possible. Showers should be mainly diurnal and diminish after sunset to the northeast as weak short wave moves by to the north. Overnight min temps warmer than previous nights with increase in the mid to upper 60s. Thursday and Thursday night...Moisture may decrease in the morning but expected to increase by afternoon as upper trough moves further east into the Mississippi Valley increasing southwest flow aloft. Still weak surface convergence across the area associated with trough/weak boundary. Upper level jet appears to be well northwest of the Carolinas but weak short wave troughs possible. Model differences noted on location of precip with GFS/GEFS drier than other models with focus more in the coastal northeast SC through the day. The NBM is more in line with the ECMWF with higher pops across the region. Think moisture and lift will be sufficient for high chance/likely pops mainly in the late afternoon and into the overnight. Instability may be a little stronger than Wednesday but severe thunderstorm threat appears low. some potential for locally heavy rain in the evening with the ECMWF ensemble and Nam model suggesting qpf > 1 inch in the north Midlands/Piedmont where surface convergence may be enhanced and strong lift associated with possible short wave trough. Max temps tricky with large spread in distributions but think a little cooler than NBM median upper went low to mid 80s most areas except CSRA where should be a little warmer. Temperatures should be above normal at night slightly. && .LONG TERM /FRIDAY THROUGH TUESDAY/... Weak frontal boundary may move into the region Friday and then may become diffuse. Upper trough to the north but some uncertainty to degree of amplification. Moisture remains high at least early in the period. Warm advection and stronger instability possible Friday may lead to more thunderstorms focused in the afternoon. Scattered mainly diurnal convection over the weekend into early next week with ensembles showing bermuda high offshore with southeast/south low level flow transporting moisture into the region. Ensembles show deep low in the southern Plains possibly closed off with some upper ridging in the southeast. But chance/slight chance pops mainly afternoon and evening each day seems reasonable and temperatures near normal. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... VFR is expected for a bit this evening, with IFR conditions expected to quickly develop later tonight. Surface analysis reveals a surface high across the Mid-Atlantic, which is pushing into the Atlantic ocean. This trend is expected to continue into the overnight hours, shifting low-level flow southeasterly as opposed to the northerly or easterly that it has been. As a result, low level moisture is expected to quickly advect into the region, with mid-upper 60s dewpoints expected in the area by tomorrow morning. On the southern edge of this high pressure system, an inverted surface trough will then push into the region and keep our weather active. Sensible weather is a bit complicated, especially when compared to recent weather. The high pressure and dry air is currently keeping things calm, but as you may have already guessed, this isn`t expected to continue. The rapid increase in moisture between 00z and 06z tonight is expected to result in the development of stratus at all TAF sites. This will first begin at OGB around 07z and then overspread the other sites between 08z and 09z. I expect it to begin with MVFR cigs but quickly become IFR thereafter. Guidance is in good agreement on this, with the LAMP, MOS guidance, and HRRR all showing this. Additionally, SREF and NBM give a >70% probability of this occurring. So confidence is fairly high that we`ll see at least IFR cigs between 08z and 13z tonight. I am not as confident as it pertains to just how far down we go. Several piece of guidance (LAMP, HRRR, and HREF) all indicate cigs falling into LIFR territory. I think that is a bit intense, but there is too much indicating it not to at least have a TEMPO group in there for it at all sites. I think OGB has the best chance of seeing LIFR conditions. Another uncertainty is whether it will be more fog than stratus. I think this sets up nicely as a stratus event, but with calm winds and a good inversion setting up, I can`t rule out fog developing. I have 4SM in there to account for this. Model soundings illustrate the differences, with some higher res models cooling the surface enough for fog while others keep us just warm enough to keep this a stratus event. If some of the higher level clouds to our west make it this way, that may be enough to favor a stratus event overall. Generally, I lean towards this line of thinking but will keep the fog in the forecast to account for the possibility. Issues will persist for a bit in the morning, but should begin to clear out towards 14z-16z as the inverted surface trough promotes lift across the region, and as the surface warms. I think showers are likely to develop as this feature pushes into the region, but I have only included SHRA at OGB where the highest chances are. Elsewhere, I would go VCSH and don`t see the need for that at this juncture. Any winds should be southeasterly through the period between 3 and 8 knots. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. && $$
Area Forecast Discussion
National Weather Service Charleston SC
1024 PM EDT Tue Jun 1 2021 .SYNOPSIS... High pressure will give way to more unsettled weather by late week. A return to more typical early June weather is possible early next week. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... As of 1020 PM: Latest nighttime RGB indicated bands of cirrus across the forecast area, with a few patches of stratus near the coast and the lower Savannah River corridor. Later tonight, mid and low clouds will increase sky cover to mostly cloudy. HRRR sfc condensation pressure deficits lower through dawn, with low values across the inland counties. I will expand the mention of patchy fog across the inland counties late tonight. In addition, CAMs indicate that shower activity will increase after 11z, peaking in coverage during the mid to late morning hours on Wed. Previous Discussion: A well pronounced upper low/ TUTT low near the Upper Keys and the southeast Florida coast will drift south through the night. In response to this feature and surface high pressure that pulls further away from Long Island and the Mid-Atlantic region, a coastal trough out near the Gulf Stream will head slowly westward, reaching near the local coastal areas closer to sunrise. There has been a few very light showers or sprinkles in a few spots of South Carolina this afternoon, due to the proximity of this trough and also the sea breeze boundary. Any isolated light rain though will end this evening as divergence becomes more pronounced over land and CINH increases. However, as the trough draws closer to shore overnight, PWat will climb to 1.50 to 1.75 inches and isentropic ascent on the 300-305K surfaces increases somewhat. That allows for isolated to scattered showers over the ocean to make it onshore of parts of South Carolina, especially the coastal counties well after midnight, or even closer to daybreak. We have just 20-30% chances as a result. While the diurnal cumulus/stratocumulus will fade this evening, additional stratocumulus will advect onshore or develop through the night. Some of these clouds will build down enough and form into an expanding stratus layer far inland. This could result in some fog forming late at night, and we have added mention of "patchy" fog along parts of the northwest and western counties, where the more favorable condensation pressure deficits are found. The boundary layer will decouple inland similar to the past few nights, but coastal winds will stay up a bit and gradually back a bit northeast with time as the coastal trough gets closer. Given higher moisture content and varying amounts of cloudiness, temperatures will not be as cool as the last two nights. We`re expecting lows generally in the lower and middle 60s inland from US-17, with upper 60s to lower 70s closer to the coast and in the Charleston/North Charleston metro regions. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/... Wednesday: Models have consistently showed that this period will mark the beginning of pattern change, from a long period of dry conditions to wetter/higher chances for rainfall. The region will be positioned between a deep Atlantic ridge well to the east and an developing upper trough over the central portion of the country. Between these two systems, deep SSE flow is expected to increase the mean layer moisture, which will lead to increasing chances for showers/thunderstorms. The best moisture and forcing is expected to be over our SC zones, where we continue chance PoPs. Lower PoPs again Wednesday night as heating/instability decreases. Thursday: the region remains within a confluent upper flow region, between the upper trough to the northwest and ridge to the east. With sufficient upper forcing, instability, and deep layer moisture, have continued afternoon high end chance to likely PoPs, highest inland due to the southeast low level flow. Model cross-sections indicate deep south-southwest flow above the surface, which could result in a potential for some training of convective cells. If training does occur, isolated areas of locally heavier rainfall could result. Friday: the upper trough to the northwest starts to weaken and move northeast of the region, but the deep layer ridge holds strong well to the east. Deep layer moisture is still in place, but upper level forcing may be a little less than Thursday. However, models show a weak surface trough/front advancing toward the area during the afternoon, which could help to organize a broken line of showers and thunderstorms. Although surface based CAPEs of 1000-1500J/Kg, bulk shear less than 30 kts. Thus, chance for any isolated severe storms seems low at this time. Model wind profiles again suggest the potential for training of convective cells, which if happens, would increase the threat for locally heavy rainfall. High temperatures expected to be near to slightly below normal through the period. However, low temperatures will likely be near to slightly above normal due to increased low level moisture and nighttime cloud cover. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... The large scale weather pattern and forecast details become much more uncertain during this period as models begin to diverge. Model consensus/blend indicate that the region will sit between an upper low/trough over central U.S. and higher pressure over the southeast U.S. and Atlantic. The upper trough is shown to generally weaken as it elongates more north-south across the central portion of the country by early next week. Meanwhile, the deep upper ridging seems to build over the eastern half of the country. Sufficient deep layer moisture appears to generally remain in place over the region, but with an overall lack of any significant upper level forcing. Therefore, it seems best to continue generally chance PoPs, centered around the afternoon hours, through the period. High temperatures expected to be near to slightly below normal through the weekend, then likely creeping back to normal by early next week. Low temperatures likely stay near to slightly above normal through the period. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... Cloud cover should increase across the terminals tonight as a sfc trough moves approaches the GA/SC coast. Forecast soundings and MOS indicate that cloud bases will gradually lower this evening into late tonight. During the pre-dawn hours, MVFR ceilings are expected over KCHS and KJZI, with patchy fog or ground fog expected at KSAV. A few light showers are possible across KCHS and KJZI during the early daylight hours, no visibility restrictions. Conditions should return to VFR by noon. Extended Aviation Outlook: Wednesday through early this weekend, with increasing deep layer moisture and upper level forcing, expect the chances for periodic flight restrictions to increase, especially during the afternoon hours each day. && .MARINE... For tonight: The inverted trough will drift west through the night, approaching the Charleston County waters closer to daybreak. As is typical with these features, the progression westward is slower than depicted by the models, so we have delayed the veering of winds by several hours as shown by the model consensus. So we hold onto easterly winds at less than 15 kt for much of the night before they turn more SE closer to daybreak. Seas as high as 4 or 5 feet into this evening will drop about a foot through the night. Mariners should be alert for isolated t-storms reaching the AMZ350 and AMZ374 waters after 3 or 4 AM. Highlights are not anticipated through the period. Deep layer high pressure will generally remain well to the east-northeast of the waters. This will produce moderate southeast to south winds of mostly 15 kts or less and seas 2 to 4 feet. Increasing chances for mainly late night and morning showers and thunderstorms. Rip Currents: A low risk is presently forecast for Wednesday. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM...NED SHORT TERM... LONG TERM... AVIATION...NED MARINE...
Area Forecast Discussion
National Weather Service Corpus Christi TX
1025 PM CDT Tue Jun 1 2021 .DISCUSSION... With most of the convection dissipating as it moves across the Rio Grande, have lowered PoPs for most of tonight. Isolated to scattered convection is still possible, particularly over the west. If storms do make it into the area, some of these may be strong. Convection is expected to pick up Wednesday, with scattered showers and thunderstorms by mid morning. Some storms could be strong to severe tomorrow, so SPC has placed us in a marginal risk for severe weather. WPC has also placed us in a marginal risk for Excessive Rainfall for Wednesday, so expect some heavy rainfall at times. This could lead to ponding on roads and rises in small creeks and streams. && .PREV DISCUSSION... /Issued 623 PM CDT Tue Jun 1 2021/ AVIATION... A tricky aviation forecast for tonight with high uncertainty in the forecast. At this time, precipitation does seem to be probable for late tonight/early Wednesday morning, it`s more the evolution of the showers and storms that are questionable. It is possible that we have a repeat of last night`s thunderstorms, though storms could be weaker with a bit more inhibition present. Should the storms present as they did last night, strong wind gusts, periods of heavy rain, and some hail is possible. However, VFR conditions are likely to continue through most of the period, with only periods of MVFR conditions expected...particularly in and around any convection that develops. PREV DISCUSSION... /Issued 441 PM CDT Tue Jun 1 2021/ SHORT TERM (Tonight through Wednesday Night)... Deterministic ECMWF/Canadian/GFS/NAM place the WRN CWA under the RRQ of a 90kt 250mb jet streak overnight/Wednesday. The NAM predicts PWAT values near/above normal during the period. Although recent HRRR time-lagged ensemble and NAM CONUS nest did not explicitly predict convection over much of the CWA tonight, feel that the combination of significant SBCAPE/limited CIN before 06z Wednesday (NAM deterministic), moisture and upper forcing may result in scattered convection over mainly the WRN CWA overnight. Anticipate convection over much of the region Wednesday afternoon. SPC maintains general convection tonight and marginal severe Wednesday, although would not be surprised if strong convection develops overnight over the WRN CWA. Coastal Flooding not anticipated based on recent/expected trends with respect to Bob Hall Pier/Port Lavaca tides and wind/sea state. Maximum Heat Index values Wednesday below 100F. LONG TERM (Thursday through Tuesday)... A trough centered around the Great Lakes region will lift to the northeast, leaving a closed low to form over Texas in its wake. As this happens, a series of disturbances will push through the area. This, coupled with a moderately unstable atmosphere, a weak cap, and an abundance of moisture, will provide the opportunity for showers and thunderstorms to develop each day this week through early next week. Some of these storms could become strong at times. Localized flooding will be a possibility as soils are already saturated, especially with slow-moving cells or training showers/storms. WPC does have most of the area in a marginal risk for excessive rainfall on Thursday, so will continue to monitor for that possibility. Interests in low-lying/flood prone areas should continue to remain vigilant and stay tuned to the forecast for the latest updates in the coming days. Rain chances show a slight decreasing trend early next week. Max temperatures on Thursday and Friday will be in the 80s across the area. Temperatures will warm into the 80s to lower 90s on Saturday and will continue to warm through early next week, with highs in the 90s inland and upper 80s along the Coastal Bend and Victoria Crossroads. As temperatures begin to rise, so will heat index values. Most of the area will see heat indices near or just above 100 Sunday through early next week. MARINE... Weak onshore flow will persist tonight through Saturday. Isolated to scattered convection may develop overnight/Wednesday. Scattered to numerous showers and thunderstorms will be possible Thursday through through Sunday. Onshore flow will increase to weak to moderate levels on Sunday. && .PRELIMINARY POINT TEMPS/POPS... Corpus Christi 73 85 73 82 72 / 30 40 60 70 50 Victoria 72 85 71 81 70 / 40 70 70 80 40 Laredo 73 89 72 85 71 / 50 60 60 70 50 Alice 71 88 71 84 70 / 30 50 70 70 50 Rockport 75 86 73 85 74 / 30 40 60 70 40 Cotulla 72 89 72 85 71 / 60 60 60 70 50 Kingsville 72 86 73 82 71 / 30 40 60 70 50 Navy Corpus 75 84 75 83 75 / 30 30 60 60 50 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ LS/77...SHORT TERM
Area Forecast Discussion
National Weather Service Dodge City KS
1041 PM CDT Tue Jun 1 2021 ...Updated Aviation... .SHORT TERM...(This afternoon through Wednesday) Issued at 1145 AM CDT Tue Jun 1 2021 Late morning water vapor satellite imagery and upper air analysis depict a trough over the northern and central plains, with a trio of vorticity maxima moving through the flow. These features have maintained the thick stratus/drizzle over southwest KS this morning, and light winds within the saturated boundary layer have fostered patchy fog over some areas. Despite upper level support, models agree the stratus deck will lift with time today, allowing for a few breaks in the clouds and at least some diurnal insolation. This will bring afternoon highs closer to normal with most areas reaching the upper 60s to low 70s, although this is somewhat dependent on how quickly the stratus can thin, and light low-level winds will not support deep boundary layer mixing lending some uncertainty in afternoon temperatures. Mid-afternoon shower/thunderstorms development is also possible mainly over the central/eastern zones, as forcing for ascent increases ahead of a vorticity max digging south-southeast during the day and overspreads roughly 500-1000 J/Kg of MUCAPE. Given the lack of any clear boundary/convergence zone, coverage will likely be limited, and most areas will stay dry. Weak mid/upper level flow will also limit wind shear and therefore storm organization, so no severe threats are expected. Later tonight, various CAMs suggest a weak/decaying MCS will move into far western KS, but again these storms will not pose any severe threat. Overnight, mostly cloudy skies will begin to deteriorate as the upper trough begins to exit to the east, and morning lows will drop into the upper 40s and low 50s. As the upper trough continues to move away during the day Wednesday, subsidence behind it, as well as ahead of a building ridge over the western states, will finally allow for mostly clear skies and appreciable daytime heating. Afternoon highs will reach into the mid/upper 70s, which is much closer to normal (mid 80s) for southwest KS this time of year. Guidance depicts 500-1000 J/Kg of MUCAPE will again develop over southwest KS Wednesday afternoon amongst 20-30 kts of bulk shear, but once again a lack of any initiating boundary and/or upper level forcing will limit convective coverage. .LONG TERM...(Wednesday night through Tuesday) Issued at 201 PM CDT Tue Jun 1 2021 The upper level pattern at the beginning of the long term period will consist of a trough over the eastern CONUS, with a ridge building over the Pacific Northwest/Great Basin and a weak cut-off low over northern Baja, Mexico. These features will move slowly east through the end of the work week, bringing dry, tranquil weather to southwest KS. Height/thickness rises will allow skies to stay mostly clear with warming afternoon highs from the low 80s Thursday to mid 80s Friday. By Saturday, the upper level pattern flattens out somewhat as the upper trough moves over the Atlantic, and broad ridging dominates the CONUS with a weak cut-off low meandering over central TX. This will not translate to much change in the weather for Saturday/Sunday, as mostly clear skies and afternoon highs in the mid/upper 80s are expected. It is worth noting that the weak cut-off low will drift slightly northward on Sunday, and a slight chance of afternoon thunderstorms clipping our far southeast zones will materialize. Weak instability/shear will preclude severe potential with any thunderstorms that can make in into southwest KS. Early next week, spatiotemporal differences emerge between guidance members regarding the cut-off low ejecting into northward into the central plains, and a separate shortwave moving into southern CA/Desert Southwest. Unsurprisingly, the GFS is the most progressive, while the preferred ECMWF solution is more reserved. In either scenario, thunderstorm chances will increase mainly across our central/eastern zones, and may pose a low-end severe threat. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) Issued at 1040 PM CDT Tue Jun 1 2021 Satellite and radar imagery at 0330z showed thunderstorm activity from near Scott City to near Syracuse to near Elkhart, moving slowly southward. HRRR suggests some of this activity will be close enough to GCK/LBL over the next few hours to warrant a VCTS/CB mention at the beginning of the 06z TAFs. Impacts will be brief and limited, if any. Otherwise, expect areas of stratus, fog and drizzle to redevelop overnight, with very light winds working in tandem with a saturated boundary layer. This potential will be focused on eastern terminals (DDC/HYS), with no reduced flight categories included for GCK/LBL. VFR is expected daylight Wednesday, with continued very light winds, variable in direction. && .PRELIMINARY POINT TEMPS/POPS... DDC 52 76 54 82 / 20 20 0 0 GCK 49 76 52 81 / 20 10 0 0 EHA 50 78 52 82 / 30 10 0 0 LBL 50 77 52 82 / 40 10 0 0 HYS 53 75 53 82 / 10 20 0 0 P28 56 75 56 82 / 20 20 10 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Springer LONG TERM...Springer AVIATION...Turner
Area Forecast Discussion
National Weather Service Grand Rapids MI
752 PM EDT Tue Jun 1 2021 LATEST UPDATE... Aviation .SYNOPSIS... Issued at 223 PM EDT Tue Jun 1 2021 - Risk for scattered afternoon showers both Wed and Thu - Above normal temperatures over the weekend into next week - Possible break in the heat with showers and storms late next week && .DISCUSSION...(This evening through next Tuesday) Issued at 223 PM EDT Tue Jun 1 2021 - Risk for scattered afternoon showers both Wed and Thu Looks like best chances for showers and a few isolated thundershowers on Wed will be along and east of U.S. 131 and north of I-94 between 1pm-9pm. On Thu...the best chance will be generally east of U.S. 127. Showers will be generally be light and quick hitters on both days. Thunder wise it might bring a 30 mph wind gust and a 30 min delay to outdoor activities but should not be any more of an impact than that. There will be a weak surge of moisture into the region tomorrow as low pressure tracks through the Ohio Valley and stays south of the area. There will also be a weak trough moving through the region which combined with the low level moisture and afternoon heating will produce instability showers (CAPE ~ 200 to 600 J/Kg) based on dewpoints in the lower 50s. How widespread and how robust the showers end up being depends primarily on low level moisture. HRRR is driest with afternoon dewpoints near 50F and just widely scattered shallow showers/sprinkles. NAMNest is on the other extreme with dewpoints nearing 60F and more numerous and deeper showers/storms. Other CAMs and NWP are inbetween with dewpoints in the low to mid 50s. Individual showers will be unorganized and short lived with weak wind fields both surface and aloft through Thursday. New activity will tend to initiate on the lake breeze and along the leading edge of an afternoon moisture surge from the SSE as well as a zone of differential heating along and north of I-94 resulting from the contrast in partial sunshine over MI with thicker clouds and cooler temps associated with the OH Valley low to our south. Subsequent showers will occur along merging outflow of prior showers (A Florida shower day in Michigan). - Above normal temperatures over the weekend into next week Almost time to take it to the bank...mid summer weather with a string of mid to upper 80s beginning Friday and continuing well into next week. Looking for a 90F reading...maybe but it does not look like the airmass will be quite warm enough to support widespread 90s this time around...but there`s still a chance at least on Sunday. The heat will be associated with a building longwave ridge aloft over the east central U.S. The center of the ridge will end up a bit SE of MI with a low level moist flow from the Gulf while a bit higher up very warm air off the high plains (H85 temps ~16C) arrives on more WSW winds. The result will yield average temps at least 10 degrees above normal with the moisture holding overnight lows in the mid 60s. It will be dry as well with little chance for rain until a week from tomorrow (next Wed). The upper ridge will suppress most chances for rain and may also help setup the potential for poor air quality towards Monday. Last thought...keep an eye on the weekend camp fires and has been very dry and the chance for fire spread will be increasing through the weekend. - Possible break in the heat with showers and storms late next week Wash...rinse...repeat is how this pattern feels. The current pattern evolution looks very similar to the our last bout of heat in mid May. Eventually the upper ridge spreads westward and flattens mid to late next week. That then allows or provides opportunity for several frontal waves riding over the ridge to drop southeastward with a backdoor cold front and a chance of storms much like our last warm stretch ended. We`ll see but that is not a bad analog looking at the end of next week. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 752 PM EDT Tue Jun 1 2021 For the most part VFR will continue to prevail tonight and Wednesday. However after 18Z Wednesday some MVFR cigs and scattered showers will begin impacting areas along and south of a AZO to LAN. Near calm winds tonight becoming southeast 5-10 kts on Wednesday. However winds at MKG becoming onshore/southwest in the afternoon. && .MARINE... Issued at 223 PM EDT Tue Jun 1 2021 Minimal wind or wave concerns next 36 hours with high pressure now over the region and only weakening over time. Winds will mostly be 10kts or less and be onshore in the afternoon and offshore late night and early morning. Any showers will stay well inland on both Wed and Thu. Some local shallow or patchy fog is possible Wed morning. Looking like south to southwest winds of 15kts or so are more likely late Thu through Sat as a new area of high pressure strengthens to the southeast of MI. The airmass will become more moist as well but the mixing associated with the increased wind gradient should squelch development of any substantial fog over the relatively cool lake waters. On that note...water temps at the coast should start to warm towards 60F with the onshore flow and very warm weather over the weekend. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. LM...None. && $$ SYNOPSIS...Cobb DISCUSSION...Cobb AVIATION...Meade MARINE...Cobb
Area Forecast Discussion
National Weather Service Houston/Galveston TX
619 PM CDT Tue Jun 1 2021 .AVIATION [00Z TAF Issuance]... Some showers are finally beginning to develop on cold front, currently over UTS and south of CLL. Some lightning is not out of the question, but should become less likely as sun goes down, so have largely pulled any mention of thunder from this set of TAFs. Expect low VFR/MVFR near and in the wake of the front briefly, but should see a return to VFR deeper into the morning. Expect rain chances to come back in the afternoon thanks to front stalling in the area - detailing the specifics on this will be difficult, but high confidence in the general idea of a stretch with multiple rounds of showers and storms this week. && .PREV DISCUSSION /Issued 326 PM CDT Tue Jun 1 2021/... .SHORT TERM [Through Wednesday Night]... A weak wind shift was aligned from about Lufkin to Houston to Sargent and this boundary was moving slowly east. Showers and thunderstorms will continue to develop ahead of this feature as it moves into LA later this afternoon. Further north, a weak cold front extended from Palestine to Caldwell to Kerrville. Models are not handling this feature well and but current thinking is that the boundary will continue a slow march toward the coast before stalling somewhere near or northwest of the I-69 corridor. With some additional heating this afternoon, it seems reasonable to expect shra/tsra to redevelop along the weak front as suggested by the 16z and 17z HRRR runs. Precipitation will wane between 05-08z with the loss of heating. Jet dynamics still show some upper level divergence this evening so think there could be a burst of locally heavy rain through the evening. Upper level winds become neutral or even slightly confluent toward morning so there should be a minimum in rain chances early Wednesday with things picking back up again toward the afternoon with a bit of heating. SE Texas will go into a RRQ by afternoon so lift along the weak front will be increasing during the afternoon and into the evening. The jet streak responsible for the rain on Wednesday will pull away from the region and the flow aloft will become semi-zonal and rain chances should diminish but not completely end as another short wave moves into the area from the west. Will stick with chance PoPs for now but these may need to be raised. Soils are saturated over much of SE TX and the potential is there for additional heavy rain but the gap in rainfall today and the significant model differences has lent enough uncertainty in the forecast to forgo a Flash Flood Watch at this time. A Watch will likely be required at some point this week but don`t think we are at that point just yet. MaxT values will remain climo through Wednesday with clouds and precip and overnight MinT values will probably remain near or just above climo due to cloud cover. 43 .LONG TERM [Thursday Through Tuesday]... Southeast Texas will continue to be prone to periods of showers and thunderstorms through this long term period (could end up being across some parts of our area almost every day) in connection with a slow moving closed low and associated disturbances. A persistent onshore flow, precipitable water values generally in a 1.5 to 2ish inch range, a possible weak low level convergence boundary setting up somewhere in the area and the potential for a healthy and somewhat prolonged divergent flow aloft all support elevated rain chances. With this slow moving (maybe even stationary) storm system setting up, locally heavy rainfall will be possible, especially where any banding or training forms. With lots of area grounds mostly saturated from recent rains, it will not take much more to cause some flooding issues, especially in/around already swollen rivers, creeks and bayous. For the rest of this week and through the upcoming weekend, widespread 4 to 6 inch rainfall totals can be expected, and locally higher amounts will likely happen. Flash Flood Watches might be needed. Stay tuned to the forecasts as the week progresses as changes are likely to happen. Make sure you closely monitor how much rain falls/ accumulates in and near your area. 42 .MARINE... Another extended period of wet weather is expected over the next week or so. A mainly southeasterly flow will persist for the remainder of the week and over the weekend while a series of disturbances bring the possibility of storms across the area. Higher winds and seas will be possible in and around the storms. Look for an increase in winds and building seas over the weekend as the result of a tightening pressure gradient. 42 && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 68 84 67 82 69 / 20 40 40 60 30 Houston (IAH) 70 85 69 83 70 / 50 50 50 70 30 Galveston (GLS) 76 84 76 82 74 / 30 40 40 50 40 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ SHORT TERM...43 LONG TERM...42 AVIATION...Luchs MARINE...42
Area Forecast Discussion
National Weather Service Indianapolis IN
1048 PM EDT Tue Jun 1 2021 ...Updated Aviation Discussion... .Forecast Update... Issued at 932 PM EDT Tue Jun 1 2021 Look for the rain showers to spread northwest across central Indiana late this evening and overnight as warm advection pattern continues and the atmosphere saturates down. The HRRR 300K isentropic analysis had a good handle as displayed in the condensation pressure deficit dropping below 30 millibars overnight. This is akin to the atmosphere saturated and radar is supporting this trend as echoes are gradually showing up further northwest over the Wabash Valley. Look for the precipitation to also increase in intensity overnight, especially over southern sections, where the precipitable water will climb over 1.5 inches. This area will also at the nose of a modest low level jet to the northeast of a surface low that will lift northeast across Arkansas. In addition, impulses in southwest flow aloft ahead of an approaching trough will also contribute. && .Short Term...(This evening through Wednesday night) Issued at 229 PM EDT Tue Jun 1 2021 Central Indiana has become encompassed in SW upper level flow, pushing a warm moist air mass aloft. This has lead to the ongoing cloud cover for the entire day, of which will continue through this evening and tonight. Even with extended cloud cover, the incumbent warmer air mass has allowed for a slight increase in high temperatures today, with most locations topping off in the mid 70s. Above 10000 feet, the air is nearly saturated causing some rain way above the surface. However, dew points in the low 50s near the ground has evaporated any precipitation prior to reaching the surface. This should start to change as a surface low develops within the low level WAA over southern IL. This surface low will provide increased lift and near surface moisture transport, enough to push dew points into the 60s. In return, rainfall should begin to reach the surface, beginning in SW portions of central Indiana, progressing to the NE overnight. PWATs will be in the 90th percentile and the troposphere will be nearly entirely saturated later tonight. This will lead to more efficient droplet growth within the cloud layers, leading to heavier rain rates. Overnight into tomorrow morning, between 1-2 inches of rain is expected over SE portions of central Indiana, with lesser amounts to the north and west. Thunderstorms chances will increase tomorrow afternoon, as a narrow window of instability will form over southern central Indiana and points southward. This is associated with an improvement of ML lapse rates ahead of a deepening surface low and some increased diabatic heating in the afternoon. The presence of an upper level jet will provide a better shear profile, but margin of error for a zone of instability will be minimal given lapse rates around 6.5 C/km. Current expectations are for isolated convective cells to develop within scattered to widespread rain showers. A near saturated layer will limit severe capable downbursts. Biggest threat for tomorrow will be localized flooding due the previous night`s rainfall and possible heavy rain rates for extended periods. Consistent cloud cover and increasing surface dew points will limit temperature gains tomorrow. Expect afternoon highs to be around 70 for most locations. && .Long Term...(Thursday through Tuesday) Issued at 229 PM EDT Tue Jun 1 2021 Rain will continue into the day Thursday as the base of a large upper level trough passes through the area. Much of the precipitation should be wrapping up by Thursday evening with models showing that the best forcing should be well into Ohio by then. Precipitation will come to an end by Thursday night with generally dry and warm conditions expected for Friday into the weekend. Models have come a bit more in line compared to yesterday when it comes to the weekend forecast. The trough that originally looked to linger over the area should fully exit by Friday with a ridge of high pressure building Friday into Saturday. Can`t rule out an isolated diurnally driven shower or storm on Saturday, but the cap looks to be strong enough to keep things dry. Sunday into Monday, warmer surface temperatures and better moisture flow will allow for slightly more widespread diurnal showers and storms, but not expecting overall coverage to be more than 20-30%. Confidence in the forecast towards the end of the period is low with divergent model solutions, especially by Tuesday. Currently think the ridge will slowly move to the east with southerly flow brining even more near surface moisture to the area. The bulk of the showers and storms should remain to the east, but with such low confidence in the forecast, the 30% POPs seem reasonable but will try and concentrate them in the 18Z-00Z timeframe when diurnally driven convection looks most likely. && .Aviation...(00Z TAF Issuance) Issued at 1048 PM EDT Tue Jun 1 2021 IMPACTS: - Flying conditions deteriorating to MVFR and worse after 07z as showers overspread the terminals. - Thunderstorms can not be ruled out, especially after 18z. That said, chances too low to put in the TAF`s. DISCUSSION: Warm advection will result in widespread showers and deteriorating flying conditions starting early overnight. Embedded thunderstorms will also be possible as surface low pressure and upper trough approach the Ohio Valley this afternoon. Winds will be southeast overnight and today less than 10 knots. && .IND WATCHES/WARNINGS/ADVISORIES... None. && $$ Update...MK Short Term...Updike Long Term...White Aviation...MK
Area Forecast Discussion
National Weather Service Marquette MI
723 PM EDT Tue Jun 1 2021 .SHORT TERM...(This evening through Wednesday) Issued at 434 PM EDT TUE JUN 1 2021 Water vapor imagery and RAP analysis show a ridge over western N America with max 500mb height anomaly of 230m centered over western WA. This ridge is forcing broad troffing downstream across central into eastern N America. Within this trof, a shortwave is over Manitoba and the Dakotas. This feature will be of interest for the fcst here on Wed. Well ahead of the shortwave, there have been weak height rises across the fcst area today. As a result, it`s been a quiet aftn under sct-bkn cu. Stabilizing flow off Lake MI has prevented any cu development closer to Lake MI. Temperatures have risen into the 70s F across the interior. Lake breezes are noted across the board under weak pres gradient/light wind regime, leading to cooler conditions with temps in the upper 50s/lwr 60s lakeside. Vis satellite imagery shows some fog across portions of northern and eastern Lake Superior. Earlier, some fog was also noted over northern Lake MI, but that has since dissipated. Tonight, upstream shortwave will be approaching Lake Superior by 12z Wed. Weak height falls are noted across the fcst area tonight, but there is little increase in winds above the nocturnal inversion despite the approaching shortwave, and there is very little theta-e advection. Thus, not expecting any shra development tonight though some of the models do generate a few shra. Will be something to monitor. Expect min temps ranging from generally the 40s south half, coolest e to the low/mid 50s near Lake Superior where stirring southerly winds will keep conditions warmer. Shortwave arrival on Wed with mid-level trof axis approaching, reaching the western fcst area in the evening, will correspond with the diurnal heating cycle. Consensus of 12z guidance is for MLCAPE to increase to roughly around 500j/kg. With instability on the limited side and deep layer shear generally under 25kt, organized storms and a svr risk are not anticipated. Greatest coverage of shra will be over the roughly the w half of the fcst area. Stabilizing southerly flow off Lake MI will work to keep the eastern fcst area dry though a few shra may develop near Lake Superior as lake breeze will attempt to move onshore, resulting in local increased convergence if it does so. Expect high temps in the 70s, except 60s lakeside of Lake MI. .LONG TERM...(Wednesday night through Tuesday) Issued at 436 PM EDT TUE JUN 1 2021 Broad troughing overhead at the beginning of the extended (00Z Thursday) moves east of our CWA by Friday afternoon. Despite weak NW flow aloft behind this wave, low level WAA kicks in immediately with 850 mb temperatures warming to near 16C by Friday afternoon and near 19C by Saturday afternoon. 850 mb are typically around 10C at this time of year indicating a prolonged stretch of much warmer than normal temperatures is expected to begin late this week. 00Z NAEFS guidance indicates 850 mb temperatures above the 90th percentile between Friday morning and Wednesday night. A subtropical trough becomes embedded within the SW flow aloft resulting in surge of Gulf of Mexico moisture early next week. I`ll start with the precipitation chances for Wednesday night through Thursday. Moist west-southwest low level flow will be in place across the CWA at 00Z Thursday as a compact, but energetic shortwave trough approaches from the northwest. Uncertainty in the timing and track of the shortwave exists, but scattered showers and thunderstorms are expected as the shortwave moves through. Wind shear is not particularly impressive, but should be sufficient for some frisky thunderstorms with small hail/gusty winds on Thursday afternoon. Storms should clear out of our area Thursday evening as the front moves through. Interestingly, the fropa acts more like a warm front than a cool front with substantial WAA expected Thursday night into Saturday morning. A surface low tracking south of the Hudson Bay on Saturday sends a cold front south that then stalls near our CWA. It`s unclear whether or not the frontal boundary will make it across Lake Superior, but substantial moisture pooling along the front will make for a muggy Saturday. The 12z ECMWF indicates convective initiation amidst >3000 J/kg of MUCAPE and ~30 knots of bulk shear on Saturday afternoon. Hodographs indicate weak veering with height that may support supercell structures. The 12z GFS was much less enthusiastic and the CMC is a somewhere in the middle. Another surface low tracking into the Hudson Bay is expected to lift the front well to our north on Sunday resulting in another hot and humid day. However, the real fun and games begin when a plume of Gulf of Mexico moisture is advected north late Monday into Tuesday. This surge of moisture is associated with a subtropical shortwave trough that gets sheared apart while becoming embedded in SW flow aloft. Overall, the synoptic scale pattern is very similar to the surge of Gulf moisture we received in mid-May. It`s therefore unclear whether or not the substantial influx of moisture will result in beneficial rainfall, but there are some indications of an increasingly active pattern by the middle of next week. Either way, a return of the muggy-meter 3000 will be needed this weekend into the middle of next week. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 707 PM EDT TUE JUN 1 2021 VFR conditions are generally anticipated through the forecast period. That said, by tomorrow afternoon, showers and thunderstorms will become increasingly likely as a disturbance approaches and crosses the region. Coverage will be the question with uncertainty as to which, if any, of the terminals will end up being directly impacted. Therefore, have included VCSH mention to provide some heads up but definitely not warranted just yet to include anything more. With the convective nature of the activity, will likely be a bit challenging to nail down those specifics until that time gets closer. As for winds, either light and variable overnight or with a general south to southwesterly component, picking up slightly early tomorrow (although not looking to exceed 10 knots, for the most part), prevailing generally out of the southwest. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 434 PM EDT TUE JUN 1 2021 Expect winds across Lake Superior to be mostly under 20kt for the next few days. A couple of periods of stronger winds are then possible. The first will be Fri night. Low pres moving across northern Ontario may result in a period of sw wind gusts to 25kt at high obs platforms, perhaps up to 25-30kt for a short time btwn the Keweenaw and Isle Royale. The second period of stronger winds may occur at some point Sat night into Sun as fairly deep low pres moves from south central Canada toward Hudson Bay with its associated cold front approaching. Although the air mass will be very warm, resulting in very stable conditions over the waters, sw to s winds could gust to 25kt at times at high obs platforms. Fog may become an issue in the coming days as air mass over the area becomes increasingly humid, but fog will definitely be more of an issue once rainfall occurs into the chilly marine layer. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...Rolfson LONG TERM...EK AVIATION...lg MARINE...Rolfson
Area Forecast Discussion
National Weather Service Nashville TN
743 PM CDT Tue Jun 1 2021 .UPDATE... FOR EVENING DISCUSSION. && .DISCUSSION... Evening sounding from OHX shows considerable moistening of the mid-levels since this morning, with some instability now evident in spite of unimpressive mid-level lapse rates. Showers have been skirting west and north of Middle Tennessee, but the HRRR finally brings more widespread activity later this evening and especially overnight. Have adjusted the POP`s accordingly as showers develop from west to east. HRRR does suggest a few heavier cells embedded in an area of mainly light showers, so we`ll leave TS in the grids from 06Z onward. Current forecast appears to be in good shape. We`ll update the public forecast later mainly for wording. No major changes are planned for now. && .AVIATION... 00Z TAF DISCUSSION. BNA/MQY/CKV/CSV...A surface system approaching from the southwest has already brought scattered activity to portions of Middle Tennessee west of Nashville, and look for showers to penetrate deeper into the mid state as the evening progresses and deeper moisture filters into the area. Expect ceilings to gradually lower to MVFR by Wednesday morning, with winds increasing from the south, and TS possible in the afternoon. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION......08 AVIATION........08
Area Forecast Discussion
National Weather Service Phoenix AZ
501 PM MST Tue Jun 1 2021 .UPDATE... Updated Aviation discussion. && .SYNOPSIS... Temperatures will warm through the middle of the week with afternoon highs in the 102 to 107 degree range along with moderate heat risk for many places through the rest of the workweek. A persistent weak upper level low and a slight uptick in moisture will result in a chance of isolated showers and thunderstorms over the higher Arizona terrain most afternoons. Showers and storms are most favored to remain north and east of Phoenix but an isolated shower or thunderstorm may survive into the lower desert areas near Phoenix. A cooling trend is possible late in the weekend and early next week as low pressure increases from the west. && .DISCUSSION... The upper level RAP mesoscale analysis indicates N to E flow aloft on the north side of a closed cut-off low circulation over offshore Baja. A small vort max in NW MX is rotating out in front of the low. The skies are mostly clear across our region with northerly flow across the western States in advance of the strong ridge of high pressure building inland. Theres also some weak elevated CAPE south of Gila County. METSAT showed mostly clear skies across the region with convective CU and isolated mostly light showers/sprinkles and an isolated storm cell on radar returns forming across N and E and SE AZ. Mid-level WV shows some slightly elevated moisture across the lower deserts and some light patchy moisture with the cut-off low near Baja. Local ACARs soundings evolution showed W flow below 700 mb and NE flow above that with some elevated moisture near H5 and an above average PW near 0.65" which is near to slightly increased from yesterday. Yesterdays high in Phoenix was 101 degrees. The month of May ended with 11 days of 100 degree plus days which is very near the normal of 100+ degree days for May in Phx. Today the warm-up continues with a highs of 102 to 104 in and around Phoenix and 103 to 106 out west. The models agree on the Baja cut-off low remaining mostly stationary through Thu as the ridge maintains strength over the West while only shifting slightly east also through Thu. As a result there is good confidence of the elevated heat persisting into Saturday. This will result in up to moderate heat risk and highs of 103-106 degrees in Phoenix and the lower deserts, and up to 104-109 out west. Highs are then expected stay close or just under this range on Sat. The lingering low pressure system will also make for low-end shower/storm chances each afternoon and evening through the late work week. The HREF family and the NMM6Km are still in good agreement on very isolated, weak high-terrain/Mogollon Rim showers/storms every afternoon and evening through Fri. These storms would be high-based storms with dry lightning and gusty outflow winds with little to no rainfall. The HRW FV3 may once again be a slightly more bullish outlier favoring slightly better coverage of storms E and near Phx. Although the low will be in position to rotate small vort disturbances across the area for a few days, it is still fairly weak and unable to attract more pronounced mid level (and BL) moisture, with the GEFs plume now showing PW spiking near 0.77" late this week. In addition there are still no IVT moisture plumes currently depicted in ensembles with this system. For Sat the Clusters analysis favors the ridge axis to the north flattening and shifting E with weak zonal troughing near the PAC NW. There is also flattened lingering high pressure and weak flow over the Desert SW along with dry conditions being favored. Tuesday Clusters depict differing positions of a W coast to W US trough with clusters 3 and 4 showing a slight potential for light QPF for central and S-Cent AZ likely associated with isolated showers and storms. There is slightly better confidence however for lower temperature from Sun and early next week associated with increasing low pressure from the W. && .AVIATION...Updated at 0000Z. South-Central Arizona including KPHX, KIWA, KSDL, and KDVT: A weak upper low is centered near the Baja Spur. Just upstream is a high amplitude ridge of high pressure with an axis near the West Coast. There is just enough moisture and instability to have isolated thunderstorms over east central AZ late this afternoon. As of this writing, the nearest storms to metro Phoenix were near Globe and producing westward moving outflow winds nearing the Gila/Pinal border. Storms are not expected to survive over the lower deserts and the outflow is anticipated to weaken substantially as it nears far southeastern portions of metro Phoenix early this evening. Confidence in a distinct wind shift at KIWA too low to reflect in the TAF at this time. Even lower confidence in that occurring at the other TAF sites. But, it bears watching. Otherwise, anticipate typical warm season surface winds with upvalley/westerly directions being favored this evening (occasional gusts 15-20kts) before transitioning to downvalley/easterly directions (well after 07Z for PHX). Upvalley/westerly directions resume midday/early afternoon Wednesday. Anticipate isolated afternoon storms over the higher terrain on Wednesday though perhaps with a little less potential for outflows to reach the metro area. As for sky cover, anticipate some minor amounts of debris cloud tonight but otherwise, no significant cloudiness. Southeast California/Southwest Arizona including KIPL and KBLH: A weak upper low is centered near the Baja Spur. Just upstream is a high amplitude ridge of high pressure with an axis near the West Coast. The end result though will be only minor amounts of high clouds and familiar warm season surface wind patterns with some afternoon gustiness (20-25kts). For KIPL, there looks to be a period tonight of south-southwest directions before resuming southeasterly. && .FIRE WEATHER... Friday through Tuesday: Isolated thunderstorms, mainly over the AZ higher terrain, could drift into portions of Maricopa and Gila Counties, including the Tonto NF Thursday-Friday. The main threats with any storms, even distant ones, will be lightning and gusty outflow winds of 25-40 mph. Otherwise, the subtle moisture increase will not do much to improve RH with afternoon values dropping into the 7-15% range and overnight recoveries mostly in the 20-35% range. Outside of outflows, winds will generally be light to occasionally moderate and follow typical diurnal/terrain influences with afternoon breeziness. && .SPOTTER INFORMATION STATEMENT... Spotters should follow standard reporting procedures. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ DISCUSSION...Sawtelle AVIATION...AJ FIRE WEATHER...Sawtelle/AD
Area Forecast Discussion
National Weather Service Pueblo CO
329 PM MDT Tue Jun 1 2021 .SHORT TERM...(This evening through Wednesday) Issued at 328 PM MDT Tue Jun 1 2021 Upper jet and wave digging southward on the back-side of central plains trough were providing the lift for scattered thunderstorms across the area this afternoon, as residual moisture due to a very wet May remains in place over srn CO. Expect scattered storms to persist into the evening hours, with HRRR suggesting a broken line of stronger convection near the KS border after 00z. Low end severe risk for wind/hail remains, especially far eastern plains where heating and resultant instability look slightly better. Activity fades after sunset, though some showers/weakening thunderstorms could linger until midnight or slightly later over the far sern corner of the plains, per the 18z NAM. Again a risk of patchy ground fog early Wed morning as ground remains moist, though weak low level nly winds may work against fog formation in some areas. On Wed, upper jet and wave move east of the area as central U.S. trough slides into the Midwest. Still some weak energy in n-nw flow aloft, plus plenty of residual moisture in place, which should fuel afternoon/evening storms over the mountains, though intensity may be weaker given lack of strong forcing. Scattered pops for the mountains, valleys and I-25 corridor look sufficient for now, as storm motion will have a fairly minimal easterly component. Max temps will warm back toward seasonal averages as heights and mid- level temps rise, and some low 80s will make a return to the lower Arkansas Valley by late afternoon. .LONG TERM...(Wednesday night through Tuesday) Issued at 328 PM MDT Tue Jun 1 2021 ...A slow warming and drying trend for southeast Colorado... Wednesday night-Friday night...Latest models continue to indicate moderate northerly flow aloft across the region into Thursday, which moderates through the day Friday, as a large upper high builds into the Great Basin. With the recent precipitation, there will be enough residual moisture in place to support scattered afternoon showers and thunderstorms for areas over and near the higher terrain, with the northerly flow aloft likely keeping storms from moving across the eastern plains. The weakening flow aloft will also lead to a lessening potential for severe weather, however, can`t totally rule out a stronger storm or two producing small hail, gusty outflow winds, and locally heavy rainfall. This will also lead to the potential for localized flash flooding, if one of these stronger storms developed or moved across the more recent scars of the Decker, Hayden Pass, Junkins or Spring burns. As for temperatures, models support a warm summer time feel by Friday, with highs warming into the 80s to lower 90s across the lower elevations, and mainly in the 60s and 70s across the higher terrain. Overnight lows also look to be more seasonal, with readings mainly in the 50s across the plains, and in the 30s and 40s across the higher terrain. Saturday-Sunday...Latest models agree the upper ridge flattens across the Central Rockies as eastern Pacific energy translates across the Northern Tier of States. While models agree on this, the latest GFS continues to be a tad further south with the Northern Tier passing system, with said energy helping to increase showers and storm coverage across the area through the weekend. The latest ECMWF and the Canadian runs, to a lesser extent, are a tad further north with the energy, and do not indicate as much of an increase in storm coverage. With that said, have stayed with current NBM pops, which brings isolated to scattered pops to areas over and near the higher terrain on Saturday and Sunday afternoon, with isolated pops spreading across the far southeast plains on Sunday afternoon and evening. Again, with only weak flow aloft, severe storm potential looks to be limited. Temperatures through the weekend look to be at at above seasonal levels, in the mid 80s to mid 90s across the lower elevations, and mainly in the 60s and 70s across the higher terrain. Monday-Tuesday...Increasing southwest flow aloft remains progged across the region into early next weekend, as a broad upper trough is progged to dig across the West Coast and into the Great Basin. Models also continue to differ on how much embedded energy will move across the Rockies, with the GFS and Canadian models more aggressive with the embedded energy than the latest ECMWF. Again, stayed with the blended model solution, which keeps isolated to scattered afternoon and evening pops, greatest over the higher terrain, along with temperatures at and above seasonal levels. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 328 PM MDT Tue Jun 1 2021 Prevailing conditions will stay VFR, with a vcts possible until until 00z-02z at all terminals as an upper level wave drops south through the state. Main risk from storms will be gusty and erratic outflow winds, though a brief period of MVFR cigs and vis will be possible with the stronger storms. Could again see some areas of fog Wed morning at all terminals, but will wait and evaluate today`s rainfall before inserting a mention in any forecast. On Wed, still a risk of tsra over the mountains in the afternoon, though chance of storms holding together long enough to reach the terminals looks low. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...PETERSEN LONG TERM...MW AVIATION...PETERSEN