Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/18/21

Area Forecast Discussion
National Weather Service Boston/Norton MA
949 PM EST Wed Nov 17 2021 .SYNOPSIS... A warm front passing to our north this evening will bring a warming trend tonight, that will give way to unseasonably mild and breezy conditions Thursday. A cold front brings showers Thursday night. Behind the front, high pressure brings dry but colder and blustery weather for Friday, followed by diminishing winds and not as cold Saturday. Beginning Sunday and especially early next week, the weather turns unsettled as a series of fronts impact the region. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... 940 PM Update: Adjusted temps and dewpoints up a bit to account for current obs, as well as increased sky cover thru 09z. Warm and moist advection pattern underway across Southern New England, with both temps and dewpoints on the rise as of this writing for most except for northern MA. Several locations in southeast MA and into eastern RI are now seeing temps in the low 50s, with dewpoints in the mid 40s! Further north, temps are in the mid 40s with mid 30s dewpoints. In between across most of interior MA and CT, temps are commonly in the mid to upper 40s. Main questions for tonight are timing when existing overcast skies break and how warm will temps get by dawn. RAP based soundings show abundant low level RH/clouds around most of the overnight, breaking up a bit by the pre-dawn hrs. Will be an unseasonably mild overnight, and high-res guidance shows temps rising well into the 50s to near 60 by daybreak across eastern and southeast MA. Lows have already been achieved in many locales, with upper 40s to upper 50s/near 60F temps by daybreak. Previous discussion: Tonight: A warm front lifts northeastward through New England tonight. Expecting considerable cloudiness across southern New England through midnight, followed by a decrease in cloud cover as dry slot associated with the warm sector moves into the area. Other than the cloud cover, expecting dry conditions, with better chances for precipitation to our north. Mild lows in the upper 30s and 40s this evening, followed by a near steady or gradual rise in temperatures, to the mid 40s to mid 50s daybreak Thursday. We maintain a SW breeze at 5 to 10 mph, with gusts 20-25 mph developing along the shoreline. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... 4 PM Update: Thursday: A mild early morning will set the stage for an unseasonably warm and breezy Thursday. Mostly to partly sunny skies prevail in the warm sector. With the sunshine and 925 mb temps in the low to mid teens C, expecting highs in the 60s- we could have a few locales in eastern MA or RI reach 70 degrees! This is not too far from record highs. The last time temps reached 70 at Boston, Providence and Hartford was on November 9th, so not too long ago. Winds at 925 mb will be SW at 35 to 40 kts, given the warmth we should be able to tap into these stronger winds. Expecting wind gusts 25 to 35 mph, highest along south coastal MA/RI, the Cape and Islands. A cold front will cross through NY State and northwestern New England during the day, and be entering the western portion of our area towards sunset. Have chance pops for rain showers in the far interior late in the day. Thursday Night: Cold front pushes through southern New England during Thursday night, bringing a period of rain showers to the area from W to E. H925 winds ahead of the front are 35 to 40 kts, could have a period of wind gusts 25 to 35 mph as the front passes through the area. Over the Cape and Islands the H925 winds are around 50 kts ahead of the front, but thermal profile doesn`t favor mixing to this level until after the frontal passage and after winds aloft diminish- potential for wind gusts 30-35 mph Cape/Islands. 12Z HREF guidance shows a plume of modest CAPE up to a few hundred J/kg for the waters just SE of Nantucket. Introduced a slight chance for thunder just offshore for late Thu evening. Across the far interior, the precipitation may change over to light snow showers or flurries before ending, with little or no accumulation expected. Anticipating overnight lows in the 30s to mid 40s, coolest in the far interior and warmest Cape/Islands. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... 4 PM update... Highlights... * Dry but colder and blustery Friday * Saturday the pick of the weekend, cool but sunny & light winds * Risk of showers later Sun with heavier showers possible Monday Temperatures... Strong cold air advection behind departing cold front Friday, with 850 mb temps crashing to about -7C, only yielding highs in the mid to upper 40s, lower 40s high terrain. Normal high is lower 50s. It will feel considerably colder given WNW winds 20-30 mph at times. Thus, blustery and cold conditions Fri. Upper air pattern is progressive, with 1030+ mb high cresting over southern New England Sat. Subsidence inversion will limit depth of boundary layer mixing, however abundant sunshine and light winds will take the edge off the cool temps Sat, with highs in the mid to upper 40s. In fact, with ensembles indicting PWATs only 40% of normal Sat, could be one of those days without a cloud in the sky. Temps rebound in the return flow Sunday, with 925 mb temps climbing to about +6C. This should support highs well into the 50s, perhaps only 45-50 in the high terrain where shallow cool air takes more time to modify/erode. Milder trend continues Monday ahead of next short wave trough and associated surface front. Highs in the 50s to near 60. Likely post frontal Tue and Wed, with blustery and colder conditions and highs only in the 40s, colder wind chills. Precipitation... Dry weather Friday and Saturday behind departing cold front early Fri. Return flow likely yields at least some showers Sunday. Not a washout but be ready to dodge scattered showers. Upper air pattern then amplifies early next week, with high amplitude trough evolving over the Great Lakes and New England. Good model agreement on showers becoming widespread Sun night into Mon. Given strong jet dynamics and abundant moisture plume, a period of heavy showers is likely sometime Monday, especially across eastern MA. Will have to watch for potential thunderstorms as dew pts rise thru the 50s and to near 60 ahead of the approaching front Monday. Then guidance differs on the amplitude and evolution of the trough. The EC and its ensembles are amplified but somewhat progressive, with secondary closed mid level low developing over the Gulf of ME and exiting into Nova Scotia. This would support blustery, colder but mainly dry weather Tue and Wed. The GEFS and GFS are much more amplified with more energy rotating thru the base of the trough and forming a secondary closed south of New England, then rotating into the Gulf of ME. This would also result in blustery and colder conditions Tue and Wed, but also would include the potential for a period of wrap around/TROWAL rain and/or snow. Teleconnections from both GEFS and ECENS both support a phase change for the NAO, AO and PNA early to middle of next week. These phase changes favor slow moving, high amplitude systems. Thus, can`t discount the stronger GFS/GEFS solutions just yet. Per WPC discussion, it`s important to note that the upper dynamics supporting this system are still within flow to the north/west of an upper low over Alaska and historically the models can have difficulty in resolving important details of amplifying shortwaves from higher latitudes until much closer to an event. && .AVIATION /03Z THURSDAY THROUGH MONDAY/... Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. 00Z TAF Update: no major changes from previous TAFs. Marginal LLWS tonight, as low level SW jet up to 45 kt at 3 kft from 03z-09z. Earlier discussion below. ===================================================================== Through 00Z: High confidence. VFR with widespread mid-high deck cloud cover. Winds become S 5-10 kt. Tonight: High confidence. Ceilings lower as warm front lifts across Southern New England. Should see a period of MVFR ceilings between 04-11Z at terminals across the interior as well as BOS. Cape/Islands/PVD should remain VFR. S to SW winds around 10 kt. SW low-level jet of 35 to 40 kt has the potential to produce low-level wind shear/turbulence after 00z. Thursday: High confidence. Mainly SCT VFR ceilings for most, though will trend more OVC across western airports ahead of a strong cold front. SW winds around 10-15 kt with gusts to 25 kt in the interior, gusts around 30 kt gusts for Cape Cod/Islands. KBOS Terminal...High Confidence in TAF. KBDL Terminal...High Confidence in TAF. Outlook /Friday through Monday/... Friday through Friday Night: VFR. Breezy. Saturday through Saturday Night: VFR. Sunday: Mainly VFR, with areas MVFR possible. Breezy. Chance SHRA. Sunday Night: Mainly MVFR, with areas VFR possible. Breezy. SHRA likely. Monday: Mainly MVFR, with local VFR possible. Breezy. SHRA likely, patchy BR. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 400 PM Update: Extended SCA headlines from this evening through Friday evening, due to anticipated period of prolonged gusty winds and rough seas. Along the southern coastal waters, gusts approaching Gale force are possible during Thursday evening. Tonight through Thursday: Moderate confidence. Tonight: Expect SW winds gusting 25 to 30 kts, and seas building to 3 to 5 feet. Thursday: S/SW winds persist, gusting 25 to 30 kts. Seas build to 5 to 8 feet offshore. Thursday Night: SW winds gusting 25 to around 30 kts during the evening- approaching Gale force. Winds become NW after midnight with gusts diminishing. A period of showers is expected, with a slight chance for thunderstorms during Thu eve along the waters S/E of Nantucket. Outlook /Friday through Monday/... Friday: Moderate risk for Small Craft Advisory winds with gusts up to 25 kt. Areas of rough seas. Slight chance of rain showers. Friday Night: Moderate risk for Small Craft Advisory winds with gusts up to 25 kt. Areas of rough seas. Saturday: Winds less than 25 kt. Seas locally approaching 5 ft. Saturday Night: Winds less than 25 kt. Sunday: Winds less than 25 kt. Seas locally approaching 5 ft. Chance of rain showers. Sunday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Seas up to 5 ft. Rain showers likely. Monday: Moderate risk for Small Craft Advisory winds with gusts up to 25 kt. Rough seas up to 10 ft. Rain showers likely, patchy fog. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory until 1 AM EST Saturday for ANZ231>234. Small Craft Advisory from 1 PM Thursday to 5 AM EST Friday for ANZ236. Small Craft Advisory until 1 AM EST Saturday for ANZ235-237- 250-251-254>256. && $$ SYNOPSIS...Nocera/NMB NEAR TERM...Nocera/Loconto/NMB SHORT TERM...NMB LONG TERM...Nocera AVIATION...Nocera/Loconto/NMB MARINE...Nocera/Loconto/NMB
Area Forecast Discussion
National Weather Service Dodge City KS
507 PM CST Wed Nov 17 2021 ...Updated Aviation... .SHORT TERM...(This evening through Thursday) Issued at 317 PM CST Wed Nov 17 2021 A band of mid level clouds extends from east-central Colorado across nw Kansas into southern Nebraska, associated largely with a mid level baroclinic zone and and the base of a cyclonically curved mid- upper level jet. Cloudiness over that region has held temperatures as cold as the upper 30s this afternoon while farther south over the DDC CWA, the cold advection has played a role in limiting temperatures to the 40s and 50 under full insolation. HRRR model suggests this thin cloud layer advects south this evening, becoming scattered out with time, as the overall surface pressure gradient relaxes and a surface anticyclone becomes established over the western half of Kansas by around 12Z Thursday. That in context, the models overall are colder than what the MOS/ and as a result the NBM are showing overall for lows overnight. It`s likely the entire forecast area is well below the freezing mark , including the red hills area, with . the western ark valley approaching the low teens. Light and variable winds early Thursday transition to breezy southwest by afternoon mainly west of roughly the highway 283 corridor as the surface high shifts southeast. A fairly homogeneous airmass will likely have little overall spread in highs across the forecast area with strong model consensus in the low 50s. Thursday night will bring slightly more breezy southwest surface winds overnight and not as cold lows given that southwest flow trajectory, and even the NBM 5th percentile is indicating mid to upper 20s, so alot of the areas especially east of Dodge city could be above the freezing mark. .LONG TERM...(Thursday night through Wednesday) Issued at 317 PM CST Wed Nov 17 2021 A moderating pattern will develop into Friday and Saturday with highs in the 60s both days as continued southerly surface winds are maintained by an overall mid level zonal cross mountain flow to the west of our region. Mixed skies through the period could complicated the temperature forecasts a little day to day. Then, reinforcing cool air returns Sunday and Monday, Sunday being the more likely windy post frontal day, although it is not particularly cold with still fall-like highs in the 50s, and dry through the period. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 504 PM CST Wed Nov 17 2021 VFR flying conditions this TAF period for all terminals. Gusty north winds are in the process of weakening, and this trend will continue through the overnight period with winds becoming light and variable by 02Z Thursday. Winds will increase once again out of the SSW at all terminals around 18Z Thursday to 12-16 kts, with gusts of 20-26 kts at GCK and possibly LBL as well. && .FIRE WEATHER... Issued at 325 PM CST Wed Nov 17 2021 Elevated Fire weather conditions will persist until the winds decouple around 5pm cst, and the temperatures begin to accelerate to the cold side. There will be a couple of hours where relative humidities dip to critical values, however the duration is not expected to reach red flag criterion on the larger scale. Gusts should cease around 5 pm with a gradual drawdown of the sustained winds thereafter. && .PRELIMINARY POINT TEMPS/POPS... DDC 20 52 33 62 / 0 0 0 0 GCK 18 51 31 61 / 0 0 0 0 EHA 20 53 33 69 / 0 0 0 0 LBL 18 52 33 66 / 0 0 0 0 HYS 20 51 32 57 / 0 0 0 0 P28 26 53 31 59 / 0 0 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Russell LONG TERM...Russell AVIATION...Springer FIRE WEATHER...Russell
Area Forecast Discussion
National Weather Service Gray ME
733 PM EST Wed Nov 17 2021 .SYNOPSIS... High pressure will give way to an approaching warm front tonight which will bring a wintry mix to the mountains with some rain showers further south. A much warmer day is in store on Thursday before a strong cold front pushes through Thursday night with a period of rain for all areas with precipitation ending as snow over the mountains Friday morning. Cooler temperatures and quieter weather is expected for Friday through the weekend. && .NEAR TERM /THROUGH THURSDAY/... 730 PM Update... The surface warm front is continuing to advance northward this evening, which is allowing for increasing shower activity across much of western ME. The 00Z KGYX sounding shows veering winds with height, indicating WAA. This is supported through observations from KMWN, where the temperature has risen by around 5 degrees over the last 5 hours. This will continue to be the trend through the remainder of the night, which will allow for mixed wintry precipitation across northern areas before the warmer air eventually wins out by tomorrow morning. Before then, a few hundredths of an inch of ice along with up to around 0.5 inches of snow/sleet will be possible across northern areas where the Winter Weather Advisory is in effect. Some adjustments to temperatures, dew points, and PoPs were made based on radar and high-resolution guidance but these adjustments were overall minor. The rest of the forecast thinking remains on track. Previously... High Impact Weather Potential: Slippery travel conditions over the north tonight. Pattern: Early afternoon water vapor imagery shows a progressive closed low at H5 centered north of Minnesota pushing east with a downstream shortwave ridge axis pushing overhead. GOES 16 infrared satellite imagery reveals a region of higher cloud tops along and northeast of a surface warm front that is pushing north and east through NY/PA forced by warm advection up the sloping frontal surface. This front will be the focus for precipitation development this evening over our northern zones...with the form of this precipitation and therefore it/s travel impacts being our primary focus. Through this Evening: Top down saturation will continue to cause clouds to thicken and lower with light precipitation likely to begin breaking out in the 7-9pm timeframe as temperatures over northern areas slip below freezing while temperatures across the south fall back into the lower 40s before stalling. Tonight: Looking at the dewpoint depressions across northern areas...there is plenty of room to cool the column this evening which will work to combat ongoing warm advection. Recent HRRR runs agree with regional radar trends and suggest that any precip during the evening will be rather spotty with better coverage after midnight with the llevel jet continuing to strengthen. By this point...a warm nose will be arriving aloft which will limit any snow potential to Somerset county...where up to an inch looks possible. As for freezing precipitation... surface temperatures should initially support freezing rain as the warm nose arrives across northern New Hampshire towards midnight...with warming temperatures pushing valley locations to rain after 1-2am with this changeover line marching north and east into Maine under broad southwest flow. The net result is the potential for up to 0.1" of ice across the inherited advisory area with the greatest amounts being at some elevation. While the heaviest precipitation looks to wait until late this evening...see no reason to change the start time of the advisory as there remains some potential for light sleet or freezing rain /and therefore slick travel/ with any precip that arrives this evening...though it will be light. Temperatures will warm through the night...with mid 30s north to mid 40s south by daybreak Thursday with all locations safely in the rain category by that point. && .SHORT TERM /THURSDAY NIGHT/... High Impact Weather Potential: Rain changing to snow Thursday night will bring the potential for deteriorating travel conditions in the mountains and points north. Pattern: Upstream trough and associated occluded surface low continues to march east through the short term period dragging a cold front east...and through our region Thursday night. With warm frontal precipitation departing Thursday morning...primary focus during the day will be on temperatures as we push into the warm sector. Focus then shifts to rain along the front...with a changeover to snow likely in the mountains Thursday night. Thursday: PTYPE should be all rain for any shower activity that remains near the international border at daybreak given T8s approaching +10C and a pattern which really doesn`t favor locking in any cold air. Southwesterly flow strengthens in the llevels during the day pushing T9s towards +10c by afternoon. This should allow temperatures to push above 60 over southern NH and into far SW ME. Further north...temps aloft will be cooler...and a good deal of cloud cover will remain with the upstream cold front bringing rain into this area before 00Z. This will keep readings in the upper 40s to around 50 in the mountains. Thursday Night: Thinning moisture plume arrives Thursday night with PWAT values in the 0.75-1" range. This moisture in the presence of substantial height falls and +DPVA will continue to promote rain along and somewhat behind the surface cold front. From a QPF standpoint...the progressive nature of the front suggests total precipitation will be relatively light with totals generally within a tenth of 0.25". More interesting is the arrival of cold air overnight which should allow precipitation to change over to snow by late evening in the mountains. This could allow for a slushy inch or two of accumulation before precipitation pulls east of the area. Temperatures here will fall into the upper 20s...with middle 30s from the foothills to the coast along with a gusty west wind. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... Mountain snow starts the period, with chances for more widespread precip early next week increasing. The exiting front Friday morning will also mean the upper trough will be dipping through New England. NW low level winds increase, amid cold air advection through the afternoon. This will lead to up-slope snow across the western mtns. Froude numbers Fri into Fri evening also indicate the chance for these winds to push occasional rain or snow showers into the foothills. This would also mean the increased chance of gusty downslope winds. With the freezing level nosing above 32 just off the surface in the coastal plain, cant count out a few snow flurries making it there as well. However, the bigger deterrent for these will be the lack of downstream convergence and moisture towards the coast. Low level winds slacken overnight as a sfc ridge moves in to crest Saturday. This will bring a pleasant, near seasonal weekend to the region. Sunny skies dominate Saturday, but there will be enough SW flow and moisture advection in the mid levels arriving on Sunday to create more cloud cast. Precip chances increase for beginning of the week. Amid return flow of exiting high pres and intensifying low pres over the western Great Lakes, moisture continues to increase in New England. Also increasing will be temps as a big push of WAA looks to arrive into the region. Model guidance brings the parent low towards James Bay, with an elongated front pushing into the east coast. Blocking of high pressure downstream will influence the orientation of the front, driving a river of moisture into the Gulf of Maine and the coast. This leans toward a warm solution for precip types, with rain across much of the CWA. The exception may be those in the western mountains where cold air holds on for a few hours during the beginning and during exit where snow may mix in. Rain tapers to showers come Tues morning as the front pushes east. Cold air once again infiltrates into the region overnight into Wednesday, with some snow showers possible across the region. There continues to be a hint of low pressure developing in the lee of the exiting front and amplifying trough. As the low near James Bay is allowed to depart, this would open the door for the closed low over the northeast to tilt negative and reform a sfc low near Nova Scotia into next Wed. Wrap around snow showers may then continue into Maine and northern New Hampshire via a TROWAL. With such a complex pattern dependent on other surrounding features not yet in place, kept probabilities on the lower side until confidence increases. && .AVIATION /01Z THURSDAY THROUGH MONDAY/... Short Term... Summary: Deteriorating conditions are expected this evening as a warm front brings some light showers to the area...with mixed precipitation possible in the mountains. Improving conditions are expected on Thursday before a strong cold front brings a band of rain to the region Thursday night. Restrictions: Conditions will deteriorate to MVFR/IFR at all terminals tonight with SHRA possible at LEB-HIE-AUG-RKD. appears temperatures will remain too warm for wintry precipitation at HIE...but a brief period of SN/PL is possible here. Conditions will gradually improve during the morning Thursday with VFR by afternoon. Another round of MVFR with possible IFR restrictions in SHRA is expected Thursday night. Winds: Winds will generally remain less than 5kts through tonight. On Thursday...southwesterly winds will strengthen to 5-10kts. Winds shift northwesterly around 10kts Thursday night. LLWS: Southwesterly winds will increase to 30-40kts this evening and continue through the night. While the LLWS should mix out during the may continue through the morning hours. Long Term... Other than SHSN and MVFR ceilings Friday at KHIE, VFR continues through the weekend. Winds will be gusty and out of the NW Friday and Friday night, becoming SW Saturday through Sun. Clouds thicken and lower into Monday as rain overspreads the area with some snow in the mountains. IFR conditions will be likely in this rain. && .MARINE... Short Term...SCAs for all waters beginning tonight and continuing through the remainder of the short term forecast period Thursday night with southerly wind strengthening tonight along with building seas. Strong southerly winds continue into Thursday night before a strong cold front shifts winds to the west before daybreak Friday. Long Term... SCA criteria winds will be possible Friday afternoon, slackening below criteria Sat AM. The offshore winds should keep higher wave heights at bay, generally 2 to 4 ft. Winds shift out of the south Sunday ahead of a strengthening system for early next week. This will result in building winds and wave heights Monday. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...Winter Weather Advisory until 5 AM EST Thursday for MEZ007>009. NH...Winter Weather Advisory until 5 AM EST Thursday for NHZ001-002. MARINE...Small Craft Advisory until 7 AM EST Friday for ANZ150>154. && $$ NEAR TERM...Tubbs SHORT TERM...Arnott LONG TERM...Cornwell
Area Forecast Discussion
National Weather Service Sacramento CA
232 PM PST Wed Nov 17 2021 .SYNOPSIS... Dry weather with late night and morning Valley fog through tomorrow. A chance of light showers late tomorrow into Friday followed by another round of breezy north to east winds. && .DISCUSSION... Upper level ridging has taken place over California today. A very weak impulse along the flow is moving over the top of the ridge, which is producing some high cirrus over Northern California. Low stratus has mostly dissipated by mid afternoon expect for a stretch around the Sacramento to Stockton metro areas. HREF and HRRR indicate the potential for Valley stratus and locally dense fog to form again late tonight through tomorrow morning under ridging. Ensemble guidance continues to show a weak weather system moving through Northern California tomorrow through Saturday. This will bring a period of showers late tomorrow through Saturday morning, mainly for the northern Sacramento Valley and mountains north of Highway 50. Moisture and QPF amounts have increased with this forecast package, though amounts will still generally be low for most areas. In the Valley, most locations will received only a few hundredths to 0.15 inch. Mountain and foothills could receive anywhere from 0.1 to 0.5 inch. This is a warmer system with snow levels above pass level, so little to snow impacts are expected. According to recent ensemble guidance, the trough forecast to move east into Nevada by early Saturday then deepen to our east through the day Saturday in a "inside slider" type pattern. This would cause surface pressure gradients to tighten and bring another round of breezy north to east winds to the area Saturday through Saturday night. -HEC && .EXTENDED DISCUSSION (Sunday THROUGH Wednesday)... On Sunday, ridging is expected to be set up over the area. Ensemble guidance suggests that a weak trough is forecast to cross the region early next week. There is significant disagreement in the clusters on placement and timing of the trough. Uncertainty is high with said disagreement, but models are leaning towards dry conditions with the troughing. Towards the end of the extended, ridging is expected to return. Temperatures are forecast to remain seasonable through the forecast period. -ACW && .AVIATION... Widespread VFR conditions through the evening. MVFR/IFR/LIFR to return to the Central Valley due to low cigs and BR/FG after 06z Thursday with improving conditions after 18-20z. Winds generally under 12 kts next 24 hours. && .STO WATCHES/WARNINGS/ADVISORIES... None. && $$
Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
716 PM EST Wed Nov 17 2021 .UPDATE... Once again, conditions are pretty quiet across the region this evening. There has been an uptick in available moisture in the mid and upper-levels as noted in the water vapor satellite imagery. This has manifested in the form of additional high cirrus clouds streaming across the central and southern portions of the peninsula. The end to a perfect day to test out our new system being implemented by folks from the Sterling Field Support Center (SFSC) for us to launch our weather balloons. Speaking of which, our first operational flight is underway. At 700mb, the SSE is helping to advect warmer and more moist air over the peninsula. Surface winds out of the east, and 500mb winds out of the SW show solid WAA through the column. The atmosphere is starting to prime for the convection expected tomorrow. As this continues into tomorrow, enough instability is expected for showers to develop (approx 800 j/kg SBCAPE based on RAP soundings). It is more questionable for thunderstorms with such weak instability. So far, MLCAPE values are only coming in with a few hundred j/kg on the RAP, likely due in part to cloud cover. However, if an updraft can grow tall enough, the atmosphere is certainly cold enough to generate some lightning, but parameters look very weak (20ish kts of shear, 30 m2/s2 sfc- 3km SRH) for severe weather, so that is good news. Some adjustments to the forecast have been made this evening to account for expected conditions overnight and tomorrow. Most notably, have added mention of patchy fog from after midnight until a little after sunrise across the Nature Coast with calm winds, high moisture, and efficient radiational cooling. At this point, no further changes are anticipated before the next forecast cycle. && .AVIATION... VFR conditions remain overnight before deteriorating conditions set in tomorrow as additional moisture and instability returns. This is expected to lead to VCSH for all terminals by the afternoon, with the possibility of MVFR to IFR CIGs setting in later in the evening. There is still some uncertainty in this yet, but trends will be monitored and TAFs will be adjusted as necessary. && .Prev Discussion... /issued 205 PM EST Wed Nov 17 2021/ DISCUSSION... Thunderstorms near/in Cuba continue to stream cirrus clouds across southern Florida with temperatures around 80 degrees. Strong moisture gradient along the Keys will begin to move north overnight and Thursday with showers and isolated thunderstorms, mainly south of Interstate 4. UPPER AIR...99 Chance of showers continues into Friday south of Interstate 4. Cold front in Oklahoma this afternoon to move through Forecast area on Friday with drier air diminishing rain chances. The exception will be in the interior counties on Saturday as Atlantic showers move into the area in/DECISION SUPPORT... the afternoon. A strong cold front moves through area on Monday with high temperatures Tue/Wed 5-10 degrees below normal ranging in the 60s in the Nature Coast and near 70 elsewhere. Coldest morning the next 7 days should be Wednesday morning with lows ranging from 39 in Williston to 51 in Fort Myers. Dry high pressure then settles over the area. MARINE... Two cold fronts will move through the coastal waters during the next 5 days; one on Friday and another one on Monday. Gusty winds behind the two fronts to elevate seas. FIRE WEATHER... Very low dispersions expected Thursday with showers and isolated thunderstorms. Otherwise, no concerns. && .Preliminary Point Temps/PoPs... TPA 68 81 69 81 / 0 50 50 20 FMY 70 81 69 81 / 20 80 70 50 GIF 66 83 68 80 / 0 50 50 30 SRQ 66 79 67 80 / 10 60 60 30 BKV 60 82 63 79 / 0 40 40 20 SPG 70 78 70 79 / 0 60 60 30 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...None. Gulf waters...None. && $$ UPDATE/AVIATION...Flannery UPPER AIR...Fleming/Twombly(SFSC) PREVIOUS DISCUSSION...Noah
Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
422 PM MST Wed Nov 17 2021 .DISCUSSION...(This Evening Through Wednesday) Issued at 130 PM MST Wed Nov 17 2021 Wash, rinse, and repeat is the forecast theme through the next week or so as fast-moving systems in northwest flow move through the area. These will be preceded by nice warm-ups, and then followed by cold-frontal passages with gusty winds and only small chances for precipitation. Overall, the deterministic and ensemble models agree reasonably well on the timing of the waves and fronts for much of the period. Temperatures mostly will be above average, but will drop to near average after frontal passages. Other than periodic breezy/windy conditions, no large- scale impactful weather is anticipated. In the short term, the strong upper low over south-central Canada was slowly moving east as a short-wave trough was rotating through the CWA. Winds were at advisory/warning levels, and should diminish by late afternoon, consistent with the current headlines. Warm advection and upper-level ridging takes over tonight and Thursday. Strong return southerly flow and a tightening MSLP gradient will result in breezy conditions Thursday, especially over the western 2/3 of the CWA. This will produce critical to near-critical fire weather conditions across Campbell County (see below). A weak upper wave will cross the CWA Thursday night, allowing for a weak Pacific cool front to move through and switch the winds to the west/northwest. A very dry air mass will result in only some mid/ high clouds, but no precipitation. Friday appears to be a nice and mild day with considerable mid/upper clouds, but with some breezy northwest winds across the eastern CWA to start. Another short- wave trough crosses the region Friday night and Saturday, but this time with more moisture (PWs near 150 percent of average), fairly steep midlevel lapse rates, and some modest Q-G forcing. This will lead to at least some precipitation, but given the drier low levels, at this time most PoPs are confined to the higher terrain areas. The NAM is more bullish on precipitation, but may be experiencing some feedback issues. Yet another upper low passes to our northeast late Saturday night and Sunday, trailing a short-wave trough and cold front across the CWA. This will bring even colder and breezier conditions Sunday versus the day before. Nevertheless, more upper ridging and warming is advertised Monday into Tuesday, with models then agreeing on another notable trough to move through the CWA late Tuesday through Wednesday. This wash-rinse-repeat pattern likely will continue a while after that. && .AVIATION...(For the 00Z TAFS Through 00Z Thursday Evening) Issued At 420 PM MST Wed Nov 17 2021 VFR conditions are expected through the period. Gusty northwesterly winds will diminish this evening, become light and variable overnight, then breezy out of the south for Thursday afternoon. && .FIRE WEATHER... Issued At 130 PM MST Wed Nov 17 2021 Strong return southerly flow will develop across northeastern WY on Thursday, especially Campbell County. The relative humidity is forecast to drop to 15-18 percent, but may be a bit lower than that if strong mixing occurs and brings down even drier air from aloft. Have adjusted dewpoints lower, consistent with the RAP model guidance and examination of some soundings for that area. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...Wind Advisory until 5 PM MST /6 PM CST/ this afternoon for SDZ025-026-032-043-044-046-047-049-072. High Wind Warning until 5 PM MST this afternoon for SDZ001-002- 012>014-031-073. WY...High Wind Warning until 5 PM MST this afternoon for WYZ071. Fire Weather Watch from Thursday morning through Thursday afternoon for WYZ314-315. && $$ DISCUSSION...Bunkers AVIATION...15 FIRE WEATHER...Bunkers