Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/16/21

Area Forecast Discussion
National Weather Service Birmingham AL
754 PM CDT Fri Oct 15 2021 .UPDATE... Evening Update and 00Z Aviation. && .SHORT TERM... /Updated at 0707 PM CDT Fri Oct 15 2021/ A few showers have affected the far northwest near Hamilton and Hackleburg, elsewhere, mostly clear conditions early this evening. High temperatures topped out between 82 and 90 degrees. The warmer areas west and south were near record highs, but fell just short. A strong cold front was located immediately behind the showers and thunderstorms in northwest Mississippi. A few of the storms have produced gusty winds and some hail. The latest RAP analysis has MLCAPE values just over 1000, which is already decreasing. Values will continue decreasing the next several hours but we may realize values around 500 in far northwest Alabama. Low level and mid level lapse rates are rather poor while K-indices were only around 30 in spots. Bulk shear will also decrease as the main system moves away from the area. There will also be a decrease of near surface convergence with time. Most of the model output this evening has the same result as earlier runs. The overall coverage of the showers/storms will decrease overnight. No severe storms are anticipated at this time. Only minor changes to temperature trend and pops this evening, with the overall theme well covered. 75 Previous short-term discussion: /Updated at 0105 PM CDT Fri Oct 15 2021/ Through Saturday. A major pattern change is on our doorstep as a longwave trough quickly moves across the CONUS today through the weekend. This afternoon could be our last "summer-like" day that we experience in 2021 with temps in the 80s and muggy dewpoints close to 70. A very strong fall cold front will be moving through the area overnight tonight, and we`ll be watching showers and a few storms as they move into our northwestern counties mainly between 10pm tonight and 3am Saturday morning. Looking at the latest high-res guidance trends, the chance of any activity reaching severe criteria will continue to be quite low, as there will be sufficient 0-6km bulk shear, but low-level instability will be waning and decreasing with time as we go into the overnight hours. The 3km NAM is depicting the best shear and instability combo just ahead of the front in our far northwest counties, but seems to be overestimating the amount of SBCAPE, with temps in the mid to upper 70s at the surface. Other high-res guidance indications are for lesser amounts of instability available by the time that the front moves into the northwest. With that in mind, locally we`ll continue to not mention any chance of severe storms just yet, but certainly can`t rule out a strong storm or two, especially if we`re able to get some mesoscale boundary interactions to enhance a few updrafts. We`ll keep an eye on the latest trends as we go into the evening. In terms of the forecast, adjustments have been made in terms of the overall PoP gradient that we`ll see as the front moves through Central Alabama. As the front moves farther to the east, the line of showers will quickly diminish in coverage, becoming scattered and then completely drying out by the time it reaches our far east and southeast counties. Locations such as Auburn, Troy, and Eufaula may not see any rain as the front moves through, as upper dynamics pass well off to our north and low-level moisture gets cut off. Behind the front, we`ll see the coolest and driest airmass so far this season, much cooler than what we saw back in September. After the abnormally warm days we`ve had lately, it will be quite a shock with a very brisk northwesterly wind prevailing between 10 and 15mph with gusts between 20 and 30mph at times. I`ve opted to go with more of a raw model guidance trend instead of NBM for winds, dewpoints, and temperatures to better realize the shallow colder and drier airmass that we`ll see moving in. We certainly can`t rule out some dewpoints in the upper 30s by Saturday afternoon in the far north as clouds quickly clear out of the area. Get ready to dust off those jackets! 56/GDG .LONG TERM... /Updated at 0237 PM CDT Fri Oct 15 2021/ Trended lows Sunday and Monday mornings toward raw guidance, with temperatures in the 40s both mornings. Would not rule out a few temps in the upper 30s across the far north in the typically cooler locations. No other changes needed for the extended this afternoon. Cooler and drier weather remains in place through the middle of the week. 14 Previous long-term discussion: /Updated at 0327 AM CDT Fri Oct 15 2021/ Sunday through Thursday. Cooler temperatures expected for the start of next week. The cold front is well to our south and east by early Sunday morning with the colder air mass advecting into the region and high pressure building across the Gulf States. Low temperatures Sunday morning will be in the 40s for most of Central AL with some of the colder valley locations potentially dropping into the upper 30s. Clear skies and mild continues will continue through the early part of next week as the surface high persists and slowly builds eastward. We`ll likely see a slight warming trend as we approach the middle to late part of next week as the center of the high is just to our east, allowing for some weak southerly flow across the region. Our next trough and potential frontal boundary approach the Southeastern CONUS towards the end of next week, but timing differences in guidance leads to some uncertainty in regards to PoPs on Thursday. I`ve trended rain chances up to 20-30%, but I`m sure that`ll change over the next few days when guidance comes into closer agreement on the front`s timing. 25/Owen && .AVIATION... 00Z TAF Discussion. A strong cold front will move into Central Alabama tonight and exit fairly quickly Saturday morning. Mentioned showers and MVFR ceilings along the front as it moves through, It appears that the precip/ceiling restrictions will be at any terminal about 6 hours. Light and variable to south southwest winds will veer to the west and then northwest into Saturday. The pressure gradient tightens quite a bit and expect winds to increase ahead of the front and remain higher behind the front. Winds gusts into the 20-25kt range will be possible with any shower overnight and behind the front. Note: AMD NOT SKED is appended at KBHM due to ASOS power loss until further notice. 75 && .FIRE WEATHER... A cold front will bring increasing cloud cover and chances for showers through tomorrow morning. Frontal passage will bring a distinct transition to northwesterly winds at 12-18 mph, with higher gusts, through Saturday morning and afternoon. Much cooler and drier air will follow. Thus, minimum RH values will trend toward the 30-50% range Saturday, and be below 40% for the entire forecast area on Sunday and Monday. Dry weather is forecast for much of next week. && .PRELIMINARY POINT TEMPS/POPS... Gadsden 59 67 40 68 41 / 80 0 0 0 0 Anniston 63 68 44 70 44 / 60 10 0 0 0 Birmingham 58 67 46 68 46 / 80 0 0 0 0 Tuscaloosa 58 70 45 70 45 / 70 0 0 0 0 Calera 61 68 46 69 45 / 60 0 0 0 0 Auburn 67 72 47 70 46 / 10 10 0 0 0 Montgomery 67 74 46 73 46 / 30 10 0 0 0 Troy 68 74 46 72 46 / 10 10 0 0 0 && .BMX WATCHES/WARNINGS/ADVISORIES/... None. && $$
Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
638 PM CDT Fri Oct 15 2021 .DISCUSSION...Updated for latest aviation discussion below. && .AVIATION...VFR conditions will continue into early evening across all aerodromes. A cold front will move through the area overnight tonight into Saturday morning. Ahead of the front showers and thunderstorms will be possible across all aerodromes reducing visibilities to MVFR late tonight to around daybreak Saturday. Winds will increase behind the front with gusty northerly winds of 20 to 25 kts and sky conditions will improve with VFR conditions returning. && .PREV DISCUSSION... /issued 255 PM CDT Fri Oct 15 2021/ SHORT TERM (Now through Saturday Night): Tonight is the night that the cold front comes through Deep South Texas! Models are in good agreement for the timing of the front to move through around 06- 12z Saturday, however, the CWA will see some isolated showers and thunderstorms before the front this Friday evening. The HRRR has a few clusters of thunderstorms moving into the northern Ranchlands around 22z Friday and moving south down the center of the CWA towards Hidalgo county by 02-03z Saturday. Right behind those storms, we can expect the front to make its way to Deep South Texas by midnight and exit the area by Saturday morning leaving us with a dry, cool air mass. Winds will become northerly and quite breezy with gusts up to 20 kts due to the FROPA. Models have shown these northerly winds to increase rapidly especially over the Gulf Waters/Coastal County areas. A Wind Advisory has been issued for the coastal counties of Kenedy, Willacy, and Cameron as well as a Gale Warning for the Gulf Waters. Both are issued for 03-15z Saturday. Dewpoints will begin to fall to 40-50 degrees by 12z Saturday morning making for a pleasant autumn-like Saturday with mostly cloudy skies and high temperatures in the upper 70s to lower 80s. We will also see a cooler than average Saturday evening as northerly winds die down and temperatures drop to the mid 50s and 60s for the CWA. LONG TERM (Sunday through Friday): High pressure will be in full control on Sunday maintaining a cool and subsident airmass over the Rio Grande Valley. Temperatures will continue to be well below normal on Sunday with northerly winds in place. High pressure then will shift eastward late Sunday into Monday, allowing for easterly and southeasterly moisture return flow to set back in. This will favor a gradual warming trend through the early portions of the coming week. A series of weak midlevel waves and disturbances will then begin to approach the region starting on Wednesday. These midlevel features may combine with increasing moisture at lower and midlevels to introduce rain chances back into the forecast from Wednesday through Friday. Confidence in exact timing and magnitude of rainfall remains low given the relatively weak and diffuse nature of the midlevel features. MARINE (Now through Saturday Night): Light to moderate onshore flow will continue until the cold front passes through overnight tonight. Winds can be expected to change to northerly by around 06z with rapid intensification with gusts up to 35 kts. Seas will begin to build by early Saturday morning reaching 8 to 9 feet with occasional seas up to 10 feet by tomorrow afternoon. As mentioned in the discussion above, a Gale Warning has been issued for the Gulf Waters from 03-15z Saturday. Winds and seas start to subside by Saturday evening. As seas come down, Small Craft Advisory may still be needed through the rest of the period after the Gale Warning expires. Sunday through Wednesday: Low-end SCEC criteria may be ongoing early Sunday morning in the wake of Saturdays cold front. Winds and seas will gradually improve on Sunday as high pressure builds into the area. Light to moderate winds and seas are then anticipated for much of the period. Chances for showers and thunderstorms then look to return on Wednesday as moisture at lower and middle levels increases. && .PRELIMINARY POINT TEMPS/POPS... BAYVIEW/PORT ISABEL 71 79 63 79 / 60 10 0 0 BROWNSVILLE 70 80 61 81 / 60 20 0 10 HARLINGEN 67 79 58 80 / 60 10 0 0 MCALLEN 66 79 57 80 / 60 20 0 0 RIO GRANDE CITY 65 82 56 81 / 50 10 0 0 SOUTH PADRE ISLAND 74 79 71 77 / 60 20 0 10 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...Wind Advisory from 10 PM this evening to 10 AM CDT Saturday for TXZ256-257-351. GM...Gale Warning from 10 PM this evening to 10 AM CDT Saturday for GMZ130-132-135-150-155-170-175. && $$ This product is also available on the web at: 68-McGinnis/Aviation
Area Forecast Discussion
National Weather Service Caribou ME
1039 PM EDT Fri Oct 15 2021 .SYNOPSIS... A warm front will lift across the region tonight into Saturday. A cold front will approach Saturday evening then cross the area early Sunday morning. An upper level low will remain over the region Monday into Tuesday, then move into the Maritimes Wednesday. && .NEAR TERM /THROUGH SATURDAY/... 1040 PM Update: Showers were across nrn and srn areas this evening per the latest radar loop. More of the activity. Some sites reporting some drizzle such as across the central highlands. This is confirmed by the latest LAPS and RAP soundings showing the deep llvl moisture and a light SE wind w/a dry wedge above 800mbs. Some slight adjustment was done to the pops to align better w/the radar trends, but overall, daycrew had things lined up well w/timing and placement. Temps/dewpoints were modified to match up w/the latest obs. No other changes needed attm. Previous Discussion... With the exception of far northeastern Aroostook County, skies remain overcast this afternoon with drizzle, isolated showers, and patchy fog across the Central Highlands into Downeast Maine. An upper level trough will move across the Great Lakes tonight. Surface low pressure will develop ahead of the trough and progress into southern Quebec by Saturday morning. Warm advection and isentropic lift will intensify ahead of the low, leading to a period of scattered showers and rain from about 6z tonight to mid to late Saturday afternoon. A modest amount of elevated instability will also lead to the possibility of an isolated thunderstorm. Precipitation amounts will generally be under a half inch with this initial round of precipitation. The area is expected to be within the warm sector by Saturday evening with the best chance of rain across the far north from about 18 to 0z. Temperatures are expected to remain mild overnight with lows in the low to mid 50s. Highs are expected to reach the low to mid 60s, with the warmest readings across the west as a strong low level jet develops and transports warmer air northward. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... Entire CWA likely to be in warm sector by Sat evening with sfc low sitting in Quebec as a cold front extends south through New England by 00z Sunday. Bulk of the rain will be over the St. John Vly and in the North Woods initially, pushing east drg the overnight. Enough elevated instability looks to be present to continue slgt chcs for thunder just ahead of the cold front as it races thru the area. PW values surge to between 3 and 4 standard deviations above seasonal norms, leading to locally hvy rain at times in any storms that can develop. Fortunately front wl be a fast-mover, thus very little in the way of hydro problems are expected. Temps wl drop back into the 40s over the North Woods where fropa occurs first with lwr 50s expected elsewhere for Sun morning. Low pressure heads into the Maritimes on Sunday though upr lvl low wl continue to plague the region into early next week due to blocking high setting up over Greenland. As the low spins acrs the northeast, H5 cold pool wl likely spark showers throughout the end of the short term. Highs on Sunday wl climb again to above normal though the warmer temps wl be on the opposite side of CWA compared to Saturday with m60s over Downeast and m50s acrs portions of the North Woods. Temps wl fall closer to normal Sun night and Monday as nw flow continues over the region. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... The long term continues to feature upr lvl troffing acrs the ern half of the U.S. through the middle of next week. Showery and cool conditions continue thru Wednesday. Hv followed NBM with shower-free possible after 00z Thu but ensembles indicate low level troffing wl continue to plague the region thru Wed night before ridging noses into the area. Depending on how quickly trof can eject ewrd may see snow showers mixing in with the rain in the morning hours. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... NEAR TERM: Predominantly MVFR ceilings this evening, becoming IFR to LIFR tonight with rain and fog. MVFR/IFR ceilings continue into Saturday. LLWS develops Saturday afternoon and evening. SHORT TERM: Sat night...Widespread IFR in low clouds and visibilities in rain. S 10-15 and gusty becoming W late. LLWS possible. Sun-Wed...MVFR in sct showers and low cigs. WNW 5-15kts. && .MARINE... NEAR TERM: Winds and seas will increase to SCA levels around midday Saturday, with an SCA beginning at 11AM. Rain and fog will reduce visibility later tonight into Saturday morning. SHORT TERM: SCA remains in effect through Sunday morning as winds gust to between 25-30kts overnight and seas over 5ft in southerly swell. Seas may remain elevated into Sun afternoon with a possible extension of SCA by several hours. Winds quickly diminish late morning. SCA conditions may again be possible Tue with wind gusts approaching 25kts. && .EQUIPMENT... The KCBW WSR-88D is back on line. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...None. MARINE...Small Craft Advisory from 11 AM Saturday to 11 AM EDT Sunday for ANZ050>052. && $$ Near Term...Hewitt
National Weather Service Eureka CA
236 PM PDT Fri Oct 15 2021 .SYNOPSIS...Mild afternoon temperatures and dry weather will occur for one more day on Saturday. Thereafter, rain will spread east across the region during Sunday. Another period of dry weather is expected on Monday, followed by additional rainfall during Tuesday and Wednesday. && .DISCUSSION...A broad low amplitude upper level ridge was shifting east across the region this afternoon. Mostly clear skies were associated with the ridge, and inland valley temperatures have responded by warming into the 70s and 80s...while cooler onshore flow occurring in the vicinity of the coast favored highs in the upper 50s to 60s. Temperatures across inland valleys tonight are not forecast to be as cold as the past couple of nights, and that will preclude frost/freeze concerns. Otherwise, marine stratus and patchy fog will be probable near the Humboldt/Del Norte coast. After another mild day on Saturday, a pattern change associated with a digging upper level trough is forecast to occur over the NERN PAC. A cold front associated with the trough will advance east-southeast toward NWRN CA during Sunday morning...with south winds locally gusting from 15 to 30 mph across exposed ridges. Rain will then move onshore across Del Norte and Humboldt Counties during midday Sunday, followed by rainfall entering Trinity County as well as Lake/Mendocino Counties Sunday afternoon and evening. Rainfall totals will generally range from 0.5-1.0 inch in Del Norte County to less than a quarter of an inch in Lake and southern Mendocino Counties as well as far eastern Trinity County. After the rain episode on Sunday, drier weather will occur across the region Monday as a shortwave ridge progresses east over the west coast. Another period of frontal rains, and pre-frontal gusty southerlies is then expected Tuesday afternoon and night, which will be followed by post frontal showers and maybe even a thunderstorm during Wednesday. Another frontal passage will be possible Friday and Saturday, which would favor additional rainfall. However, uncertainty remains high with that late week scenario due to differing model solutions related to the eastward progression of the front. Garner && .AVIATION...As expected, coastal stratus made a reappearance last night, with some low ceilings and fog along the coast, particularly along the N and central Humboldt County coast. A patch of stratus lingers just offshore as of this writing, although land areas are mostly clear. Expect coastal stratus to expand and spread inland this evening and overnight N of Cape Mendocino as the marine layer deepens and the low-level inversion strengthens a bit. This should result in coastal clouds lingering for longer along the coast Saturday morning. The marine layer still looks to be too shallow for any low-level moisture to make it to KUKI from the W, and the HRRR doesn`t indicated any stratus making it up the Russian River Valley from the S. Winds will be light. /SEC && .MARINE...High pressure will be shunted south toward the region during the next 24 hours, and will aid in weakening winds across the coastal waters. A frontal boundary will then advance southeast across the area Sunday. South winds ahead of the front will become moderately gusty out of the north behind the front. Thereafter, another period of weak winds is expected to occur on Monday, followed by possible gale force southerlies during Tuesday and Wednesday. Garner && .EKA WATCHES/WARNINGS/ADVISORIES... CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 11 PM PDT this evening for PZZ475. && $$ Visit us at Follow us on Facebook and Twitter at: For forecast zone information see the forecast zone map online:
Area Forecast Discussion
National Weather Service Gray ME
933 PM EDT Fri Oct 15 2021 .SYNOPSIS... A warm front lifts northward through the area Saturday leading to another unseasonably warm day with breezy southerly winds. A cold front crosses the area Saturday evening into Sunday morning bringing areas of rain, gusty winds, and some thunderstorms. Cooler conditions arrive for the start of the next week with daytime showers in northwest flow. High pressure and quiet weather return for the midweek period. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... 930 PM Update... Quick update was made, focusing mostly on PoPs as well as fog/drizzle areal coverage for the overnight hours. Fog and low stratus are expected to persist through the night under a very warm and moist airmass. Also, PoPs were adjusted upwards through the overnight hours across portions of southern and central NH based on trends in radar and near-term forecast guidance such as the HRRR and HREF. The rest of the forecast remains on track. Update... Plenty of moisture across the region overnight with mainly cloudy skies. Some dense fog has moved into the Midcoast region of Maine and have adjusted the near term portion of the weather forecast in terms of fog coverage and low visibilities. Otherwise, most areas are rainfree except for a few light showers in the mountains. The latest mesoscale models continue to show a few light showers moving across the region tonight, with the precipitation mainly away from the coastline. Have made minor adjustments to the overnight pop forecast as well as temperatures and winds. The latest HREF solution continues to show plenty of low level cloud cover over the region until partial clearing occurs over New Hampshire by Saturday afternoon. Prev Disc... Frontal boundary bisecting the forecast area will remain nearly stationary through tonight into Saturday morning. Low pressure will be taking shape this afternoon and evening over the Ohio Valley and will deepen tonight as it tracks northeastward thanks to a trough at H5 going slightly negative tilt. As this trough goes negative tilt, it will send a belt of enhance low level southwesterly flow into upstate NY and then western New England by Saturday morning with winds at H7 approaching 50 kts. This belt of enhanced SW flow along with deepening low pressure will send the stationary front northward as a warm front towards daybreak Saturday morning. In the meantime, the stationary boundary will provide a focus for showers tonight, along with plenty of low clouds and patchy fog. Onshore flow on the north side of the stationary boundary coupled with some lift will also bring patchy drizzle along the Mid-Coast into the Capital District of Maine. Lows will generally be in the 50s to low 60s across southern New Hampshire. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY/... Saturday morning the boundary will sail northeastward as a warm front and is expected to push through northeastern zones during the afternoon. Showers are expected along and ahead of the front and with PWATs in the 1 to 1.5 inch range they will be capable of some moderate rainfall. Expect a drying trend from SW to NE with skies turning partly cloudy late morning into early afternoon as much of the area becomes enveloped in the warm sector. Southerly winds will also ramp up during the morning as the belt 50 kts winds at 700 mb slides eastward across upstate NY and VT. This belt of winds is expected to weaken slightly as it crosses NH into Maine and with BUFKIT soundings across the area showing a strong inversion around 850 mb expectations are for these strong winds to not mix to the surface. Regardless, it will be breezy with gusts in the 20 to 30 mph range late morning into the afternoon. As much of the area will be within the warm sector highs will climb into the low to mid 70s across much of New hampshire into SW Maine. Northeastern zones will see less sunshine limiting the highs there in the mid 60s. Late Saturday afternoon into Saturday night low pressure will track northeastward through the St Lawrence Valley dragging a cold front across northern New England. CAMs are in relatively good agreement in developing a broken line of convection along the front in upstate NY Saturday afternoon with this convection forming into a fine line as it tracks into VT late in the afternoon. CAMs start to diverge some with how the fine line holds together as it crosses into New Hampshire. There is also a signal for a secondary belt of enhanced low level winds with the fine line leading to a non-zero threat for strong to damaging winds from any convection that can drag these winds to the surface. SPC has much of New Hampshire into York County outlooked in a Marginal Risk due to this potential for winds. Overall, the timing and convective parameters are not favorable for this line of convection to hold together as it crosses into New Hampshire and am favoring CAM solutions showing this line of convection weakening as it crosses the area. Current line of thinking is that cold front will bring a decent shot of moderate rain with embedded thunder and the potential for the strongest embedded cells to produce 35 to 45 mph wind gusts. The other potential impact from the cold frontal passage will be the combination of winds along moderate to potentially heavy rain leading to leaves dropping and causing poor drainage issues. Overall QPF amounts are generally under an inch with upwards of 1 to 1.5 inches in the mountains to the International Border. The cold front will sweep through the area by day break Sunday with any showers confined to the mountains and clearing skies downstream. Northwest winds will pick up in the wake of the front with gusts topping out around 20 mph. Downsloping will help boost temperatures into the mid 60s near the coast while northern areas will see highs only into the 50s. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... The active northern stream persists through the next work week with a trough axis crossing early... and another approaching from the west late, punctuated by a mid-week ridge of high pressure building in from the south. Temperatures will run closer to normal during this stretch with daytime highs mostly in the 50s to around 60 degrees, though a warm trend later in the week is expected with flow turning southwesterly. Drier air coming on deep northwest flow allows more room for overnight cooling as well, with lows mostly in the upper-30s (north) and 40s (most other places). A caveat is that day-to-day details are scant at this point given the active pattern and numerous areas of low pressure at play over central and eastern NOAM... thanks to an active Pacific storm track... plus we`ll be right on the cusp of a cooler airmass to the north and a warmer airmass to the south. This uncertainty is reflected in the growing ensemble spread in the h850 temperature and h500 height fields from about mid-week onward. As for details we can tease out... Sunday night through Monday and into Tuesday, after the passage of an attendant surface cold front earlier in the day, an upper level trough axis crosses the region. This will bring a northwest wind and a cold pool aloft, which will produce scattered showers in upslope regions and an uptick in shower chances over the whole region during the daytime with strong mixing. While I expect most mixed or frozen precipitation to stay well up in elevation over the mountains... wet flakes or grains can`t be ruled out across northern valleys by early Tuesday as the thermal trough dips across the international border. Strong mixing will also lead to a steady northwesterly breeze these two days... turning blustery during the day, accompanied by a mix of sun and clouds outside of the mountains which will be more overcast in upsloping flow. Meanwhile troughing over Quebec spars with ridging across the South... the former briefly yielding to the latter Wednesday into Thursday with clearing conditions and a rebound in temperatures, into the mid- 60s for most of the populated corridors. On the flip side a relaxed PGF means overnight temperatures will be coolest through the mid-week period with 30s possible outside of the mountains... though the forecast remains a conservative blend and has values closer to 40, given aforementioned sources of uncertainty. As high pressure shifts east... a warmer southerly flow develops, bringing a warming trend to the area. Major deterministic models are in general agreement WRT a compact shortwave rounding the base of a trough anchored over the Canadian Prairie late this week. The next challenge will be how that compact low ejects over the Northeast and New England. This system will impact us at some point late in the week, but whether we`re on the warmer or cooler side... and how strong it will be... is a low-confidence forecast at this time. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... Short Term...MVFR and IFR conditions will deteriorate further tonight to IFR/LIFR in lowering cigs and reduced visibility in patchy fog and SHRA. Warm front lifts north through the area Saturday with conditions improving to MVFR and VFR from SW to NE late morning into the afternoon. Southerly winds increase ahead of a cold front during the day with gusts to 20kts. Cold front brings RA with some TSRA Saturday evening and overnight with a return to IFR conditions likely. Conditions improve to VFR Sunday in clearing skies Long Term...Northwest flow persists through the first half of next week and becomes gusty during the day. For restrictions, MVFR/local IFR is possible for KHIE/KLEB with very brief restrictions possible elsewhere in -shra. VFR persists otherwise. && .MARINE... Short Term...Southerly winds increase Saturday ahead of an approaching cold front with SCA conditions likely around day break. Cold front crosses the waters Saturday night with winds shifting out of the NW. Winds and seas will drop below SCA conditions Sunday morning with potential for SCA to redevelop in NW winds Sunday afternoon. Long Term...Low pressure very gradually exits to the northeast through the first half of the next week with a steady offshore wind. Given the pattern and still-warm SSTs one could expect at least a short period of SCAs with gusty winds over the outer waters and maybe the bays. Broad high pressure builds back out over the waters by about Thursday with winds and seas diminishing. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...Small Craft Advisory from 8 AM Saturday to 8 AM EDT Sunday for ANZ150>154. && $$ NEAR TERM...Cannon/Tubbs
National Weather Service Wilmington OH
948 PM EDT Fri Oct 15 2021 .SYNOPSIS... A cold front will move through the region overnight. High pressure will begin to build in later on Saturday behind the cold front, offering dry conditions with cooler than average temperatures. An extended period of dry weather is expected through the middle of next week, with temperatures trending closer to normal for this time of year. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... A cold front, located near I-71 this evening, will push through the remainder of our region overnight. An embedded s/wv located within a broader mid level trough will move east/northeast across the area. This feature, combined with upper divergence from the RR quad of an embedded 250 mb jet, along with low level convergence above/behind the frontal surface, will result in widespread showers. A rumble of thunder will be possible along and southeast of I-71. Thus, have continued with categorical PoPs overnight. The pressure gradient will increase, allowing winds to gust from the northwest up to 25 knots at times. Temperatures will cool off, falling into the upper 40s far west to the mid 50s far east by morning. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... The cold front exits our fa Saturday morning. A few light showers may linger in west-central OH the longest, but will likely taper off by the afternoon. Meanwhile, notable clearing will begin Saturday morning across our west, with skies becoming mostly sunny for the majority of our CWA on Saturday with the exception of western and central OH. Strong winds aloft will help enhance winds at the surface. Sustained northwesterly winds of 15-20 mph are possible, with gusts up to 20-30 mph. A cooler and drier air mass settles in - providing conditions that are much more fall-like. Temperatures will struggle to break above 60 for a number of our northern counties on Saturday. Saturday night, a few clouds will traverse our northern/eastern CWA to start the night before mostly clearing out. Winds will subside some, but continue to remain around 5-10 mph overnight. Even with the winds remaining slightly on the higher side, overnight lows will plummet into the lower to middle 40s, with a few of our climatologically cooler spots dropping into the upper 30s. No mention of frost as of yet due to the winds staying up. && .LONG TERM /SUNDAY THROUGH FRIDAY/... Amplified mid/upper level flow with sharp trough over the northeast and a large ridge over the nations mid section. This places the Ohio Valley in northwest flow with surface high pressure building across the area Sunday into early next week. This high will offer drier conditions. Temperatures look to be a little below normal with highs on Sunday in the lower and middle 60s, warming slowly into the middle and upper 60s on Monday. A broad mid level ridge to build into the area with a low level west to southwest flow developing on the back side of surface high. This pattern will offer dry weather with slightly above normal temperatures into the middle of next week. Highs are expected to be in the upper 60s to the lower 70s for both Tuesday and Wednesday. Shortwave to track through the Great Lakes Thursday/Thursday night. Chances for rain showers begin to develop Wednesday night into Thursday. Some model differences exist regarding how quick pcpn ends Friday, so will limit any mention of a shower to slight chance. Temperatures turn cooler with highs Thursday ranging from 65 to 70 and 60 to 65 on Friday. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... A cold front will move southeast across the region this evening. Scattered showers, perhaps a rumble of thunder, will accompany the frontal boundary. Conditions will vary between VFR and MVFR. For the overnight period, the front will continue to move southeast. An embedded disturbance within a larger mid level trough will bring additional lift, and the result will be widespread showers as a weak surface wave ripples northeast along the exiting boundary. Conditions will lower to MVFR (ceilings between 1000 and 1500 feet and visibilities between 3 and 5 miles) with some pockets IFR ceilings possible. Showers will taper off across the west toward 12Z. In addition, winds will pick up from the northwest with gusts up to 25 knots possible. On Saturday, mid level trough will push east across the Great Lakes and Ohio Valley. Showers will end during the morning across the east with some clearing expected over the west. By afternoon, some SCT to LCL BKN cumulus/stratocumulus can be expected in the post frontal environment. It will be breezy with west/northwest winds 10 to 15 knots and gusts up to 25 knots. Winds will diminish Saturday evening as temperatures cool and skies clear from the west. High pressure is then expected to build into the Ohio Valley. OUTLOOK... No significant weather expected. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ SYNOPSIS...Clark/Hickman NEAR TERM...Hickman SHORT TERM...Clark LONG TERM...AR AVIATION...Hickman
Area Forecast Discussion
National Weather Service New Orleans LA
952 PM CDT Fri Oct 15 2021 .EVENING UPDATE... Pop values have been decreased based on upper air, upstream Metar, Radar, Satellite, and Skew-T analysis. Thunderstorms have been removed due to the fact that the system`s thermo profile and upper level support has moved ahead of the cold front. Upstream Metar are showing that LCH is one of the few upstream sites that is showing any precip and that has been a temporary condition. Satellite and Radar have shown that the line has become broken and the broken portion is inbound for the CWA. Finally Skew-T indices are showing decreased lapse rates, strong mid level inversion, and a increased CIN. Overall the trends are more towards a stratus deck and rain showers. && .PREV DISCUSSION... /issued 629 PM CDT Fri Oct 15 2021/ AVIATION...(00Z Discussion) Conditions are expected to start at VFR until the front reaches the stations. The front is expected to hit each station between 04Z and 07Z, with CIG`s dropping to MVFR and VCSH/VCTS around the station. Once frontal passage occurs conditions will improve to VFR, however winds will increase and gust, with wind shear conditions expected at KBTR and KMCB. -KO PREV DISCUSSION... /issued 337 PM CDT Fri Oct 15 2021/ SHORT TERM (This evening through Sunday Night)... Starting off with this afternoon/evening, main focus is on developing Cu/spotty showers across the Atchafalaya Basin. Quick mesoanalysis earlier this morning indicated zone of moist convergence primarily from the surface to low-levels along a meridional oriented axis from near Morgan City, north to around BTR. Investigating the environmental set up, we warmed up into the upper 80`s quickly this afternoon which led to a well-mixed PBL with patchy cumulus and an overall warm, but pleasant day. The same subsidence inversion responsible for keeping us dry for the past several days has finally lifted and weakened due to deep- moist ascent in place over the region, but the residual airmass aloft remains still warm and dry, owing to a very warm thermal profile aloft (H7 to H5 Lapse Rates ranging 5 to 5.5C/km and H5 temps in the -5C range). So regardless of ample surface warming, we only revealed very little "thin" cape aloft in an environment lacking large-scale lift. Meaning, we need some "trigger" to get showers/storms going, and that is where this moist convergence axis comes into play. Interesting to note such impressive consistency in the HRRR late this morning/early afternoon with each run very confident over the idea of scattered showers/storms igniting along this axis and spreading east through this evening. Recent GOES-16 Cloud Phase Distinction RGB illustrates growing cumulonimbus in this region, and given such overall support, will ride with this forecast. Not anticipating any strong or severe storms due to such an unimpressive environmental profile, but still enough to deliver a quick burst of heavy rain for some across southeastern LA, primarily from Baton Rouge to Slidell including New Orleans. This activity will come to an end later this evening as this axis weakens revealing prevailing southwesterly surface winds. Then focus shifts to a cold front racing our way from the west and northwest later tonight. We will see showers/storms ignite along the front later this afternoon along coastal SE Texas northeast into northern LA and MS, which will drift east with time reaching our NW CWA areas around 10PM to 12AM. As mentioned before, with the lack of large-scale forcing, the only lift will be along the front itself as it races east overnight. Even after decoupling, we still will have just a slither of enough elevated instability lingering to produce a few rumbles of thunder along a thin, broken line of showers. Kept what was done in the morning update by removing thunder for far northeastern parts of the CWA from around Walthall Co, MS to Pearl River and Pascagoula, as instability really lessens going into the overnight hours, as does the line itself weakening and slowly dissipating as the front swings through coastal waters. It is very possible a few folks, especially south of I-10/12 in a region of less overall frontogenetic forcing will not see any rain, but for many, a quick tenth to quarter inch will come for many out of this passing line. The front roars through early Saturday with gusty northerly winds to follow. It is looking pretty breezy for everyone during the day on Saturday with clearing skies behind the front. Some of the windiest locations near or along north-facing shorelines (including the southshore and parts of SE LA). Will have to monitor the need for a Wind Advisory in this region, but otherwise winds will be strong over marine areas. Continuing with the 90th Percentile NBM bias for marine areas, with a NBM/90th Pct blend for inland locations as strong cold air advection dominates the area. Will have to watch if pressure gradient winds can relax enough to aid in radiational cooling processes and cool us down below blended guidance Sunday morning. Just not looking like we shut off completely looking through probabilistic wind guidance, especially given our proximity so far away from the surface high anchored to the northwest. Because of this, not as aggressive with lows but still on a cooler bias slowly lower than deterministic NBM guidance. Going into Sunday, we will start to see upper-level cirrus advecting in from the west in response to a weak shortwave approaching the area from the west-southwest over northern Mexico/Texas areas. The big question remains is how much cloud cover will be possible late Sunday night and into Monday morning, as by this time the high pressure area settles in close enough to the northern Gulf coast to relax surface winds helping to promote radiational cooling. Should clouds be thick and low enough to develop/advect into the region, we may be more near deterministic NBM suggested values, if not a degree or two warmer. However, a closer look at model soundings shows a great deal of dry air in the H5 layer to the surface, with most of this moisture residing in the H4 to H2 typically indicating an altocumulus/cirrus deck. Just not confident enough to jump on the warmer trend entirely yet, but will stay right at or slightly lower than guidance, meaning overall, look for overnight lows a few degrees or so warmer than Sunday morning, but still chilly regardless. LONG TERM (Monday through Friday)... Going into the new work week ahead, we remain under control of strong surface high pressure drifting east of the area, shifting surface winds out of the east with time. We will not see a steady increase of moisture until around Wednesday as deep Gulf return flow takes back over with southeasterly winds building into the surface to low-levels. Long-range guidance still hinting at the next front late next week, which will bring our next rain chances. Might be a bit more rain coverage with this one as a weak impulse/shortwave rides along zonal flow over the northern Gulf over the southward sagging front to produce widespread rain/storms. This upper-level orientation typically can be concerning and lead to the front slowing down, however a secondary impulse within large-scale troughing over the eastern US will push all of this out of here revealing another nice cool down next weekend. Ofcourse, the details remain to be seen but overall, nice weather most of next week with steady moderation in temperatures. Rain chances slowly on the upward trend in the middle to later parts of next week. KLG AVIATION (18Z DISCUSSION)... Expect primarily VFR conditions for most area terminals this afternoon, only exception will be for the potential of a few SCT SHRA/TSRA generally along and west of I-55, with best chances in and around KBTR where VCSH has been mentioned for now. In any shower or storm this afternoon, expect only temporary reductions in CIG`s causing lower flight categories but will remain VFR outside any shower/storm activity before becoming dry this evening. A cold front and line of SHRA/TSRA will pass through area terminals tonight into early Saturday morning, leading to a wind shift bearing 340-360 and an increase in surface winds through daybreak and into the day on Saturday. At this time, the strongest winds will be for terminals along and near north-facing shorelines including KNEW and KMSY, but all terminals will experience gusty northerly winds throughout the day with mainly SKC otherwise. KLG MARINE... Weak onshore flow will persist this evening and into early parts of tonight, out ahead of an approaching cold front expected to swing across the region early Saturday morning. Behind this front, strong northerly winds ranging sustained fresh to gusts near strong breeze all day Saturday. With that, a Small Craft Advisory is in effect for all marine zones through early Sunday morning. Waves/seas will increase throughout the day as strong offshore flow persists, around 3 to 6ft for protected waters to 6 to 10ft for outer open Gulf waters. Peak highest wave conditions are likely Saturday night through Sunday morning, steadily lowering through the rest of SUnday through Monday. Going into early next week, winds will transition out of the east at around 8-10kts, with higher gusts with no significant impacts expected through middle to later parts of next week. KLG && .PRELIMINARY POINT TEMPS/POPS... MCB 58 72 47 73 / 30 10 0 0 BTR 60 73 49 74 / 20 10 0 0 ASD 64 77 48 76 / 30 10 0 0 MSY 67 76 59 75 / 30 10 0 0 GPT 67 77 51 75 / 30 10 0 0 PQL 67 77 49 75 / 30 10 0 0 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...Small Craft Advisory from 4 AM Saturday to 10 AM CDT Sunday for GMZ536-538-550-552-555-557-570-572-575-577. Small Craft Advisory from 4 AM to 10 PM CDT Saturday for GMZ530- 532-534. MS...None. GM...Small Craft Advisory from 4 AM Saturday to 10 AM CDT Sunday for GMZ538-550-552-555-557-570-572-575-577. Small Craft Advisory from 4 AM to 10 PM CDT Saturday for GMZ532- 534. && $$
Area Forecast Discussion
National Weather Service Paducah KY
707 PM CDT Fri Oct 15 2021 .UPDATE... Issued at 707 PM CDT Fri Oct 15 2021 Convection was progressively weakening this evening. No severe weather is expected, thus the Severe Thunderstorm Watch has been cancelled. Also updated aviation discussion. && .SHORT TERM...(Tonight through Sunday night) Issued at 328 PM CDT Fri Oct 15 2021 Scattered thunderstorms are expected to continue to develop and stream eastward across west Kentucky into the early evening. Effective shear of 40-50kts along with 500-1000J/kg of MLCAPE are apparently sufficient to support a few mini-supercells with a damaging wind and tornado threat. The HRRR continues to develop convection from central Arkansas northeastward into the Purchase Area around 00Z right as the real cold front arrives there. The 12Z HREF hit that area with its best updraft helicities, which would support more rotating storms with a damaging wind and tornado threat. The bottom line is that we will not likely not be able to cancel any portion of the watch before its expiration at 8 PM. While all of this is going on, forcing with the approaching upper trough will result in widespread showers and possibly a few rumbles of thunder over most of the region into the evening hours. The precipitation is expected to move out of the area by around 06Z and skies over the entire should be clear by 12Z Saturday. The other story is the gusty northwest winds expected this evening behind the cold front. The stronger gradient should begin to impact the northwest portions of the area around 23Z and the spread eastward over the next few hours. There will be a 3 to 4 hour period of 20-30kts gusts with sustained winds 15-20kts. It will not be a pleasant evening for outdoor activities, especially in the east. Surface high pressure will settle to our southwest late Saturday and the pressure gradient will be weak enough that much of the area will see calm winds Saturday night. With dewpoints expected to be in the upper 30s areawide, some patchy frost cannot be ruled out, especially in the sheltered valleys in southeast Missouri. Our forecast lows may not be cool enough. Saturday`s highs will be in the middle to upper 60s or several degrees below normal despite full sunshine. The airmass will modify a bit Sunday and that will lead to a slight warming trend in both highs and lows. .LONG TERM...(Monday through Friday) Issued at 328 PM CDT Fri Oct 15 2021 By Mon, the PAH forecast area will be under ridging aloft and high surface pressure, providing mostly clear and dry conditions. The surface high will continue to move slowly eastward with time as the ridge is slowly replaced by cyclonic flow to the southeast of a Midwest cyclone. The medium range models continued to indicate limited moisture return by Wed ahead of a cold front due to southwesterly to west-southwesterly low level winds. However, there should be enough moisture/lift for some scattered to isolated development of shower activity mainly Wed night with the slightest chance of a lightning strike. The National Blend of Models kept chance PoPs mainly in the eastern half of the region for Thu afternoon as the cold front continues to move through west-to-east. Thu night and Fri look dry and a bit cooler. For most of the extended forecast period, expect somewhat above average temps for this time of year, with highs in the 70s except upper 60s Fri (Day 7). Lows will be in the 40s and 50s. && .AVIATION... Issued at 707 PM CDT Fri Oct 15 2021 Shower activity was on the wane this evening, in coverage and intensity, especially south the OH River. This will reduce the likelihood of vsby restrictions due to pcpn there. However, a tstm with gusty winds is still possible through about 01Z across southwestern IN. A wind shift to the northwest should be complete across the entire area by midnight. A period of MVFR or brief IFR cigs are expected just behind the front, with rapid clearing from the west expected late evening into the overnight hours. The northwest winds will increase significantly for a few hours behind the front, sustained around 15kts with gusts 25-30kts. Winds will diminish a bit overnight and then pick back up with mixing Saturday morning. Gusts Saturday will be up to around 20kts. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...None. MO...None. IN...None. KY...None. && $$ SHORT TERM...DRS LONG TERM...DB AVIATION...DRS/DB