Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/27/23

Area Forecast Discussion
National Weather Service Charleston SC
948 PM EST Sun Feb 26 2023 .SYNOPSIS... High pressure will extend across the region into Monday. A cold front will move through the region Monday night into early Tuesday. A stronger cold front could affect the area late week. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... No major changes were made for the late evening update. Near term guidance is still pointing to a foggy overnight period across Berkeley and Charleston Counties with a potential for dense fog. The development of dense fog closer to the coast will likely have to wait until surface winds drop there a bit a bit more, but ceilings are slowly lowering suggesting stratus build-down is in progress. The main forecast concern for tonight centers on fog over parts of the Charleston Tri-County area. There are increasing signals that marine stratus developing off the Charleston County coast in the vicinity of a weak stationary front could slowly build down and transition to fog overnight as it spreads onshore. Guidance is essentially mixed on how widespread and dense the fog will become with some of the favored statistical members pointing to very little fog and stratus development, while most of the high-res members, with support from the HREF, CONShort and LAV data sets, showing a fairly significant dense fog event evolving over parts of Charleston and Berkeley Counties overnight. 1000 hPa condensation pressure deficits are not progged to become overly low south of the Santee River with only the NAM12 showing values low enough to support widespread dense fog. However, the RAP and H3R are all pointing to dense fog despite relatively high condensation pressure deficits in their respective runs. This leads fairly low confidence on how the fog situation will evolve overnight. Given the trends noted in the higher-res data, the decision was made to hit the fog forecast a bit harder, highlighting "areas of fog" for areas roughly along/north of the I-26 corridor and expanding into parts of James Island, Johns Island and West Ashley, including Downtown Charleston. Opted to old off on any mention of dense fog with low vsbys for now given the uncertainties noted above, but it is very possible Special Weather Statements and even a Dense Fog Advisory may be needed overnight as trends become more apparent. It will be a relatively warm night with lows only dropping into the upper 50s/lower 60s, except mid 50s north of the front near the Santee River. && .SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/... Low amplitude short-wave ridging/larger scale subsidence will be in place across the SE CONUS to start the period. Strong mid-level short-wave and attending surface low pressure will be advancing up into the Great Lakes region which will nudge a weakening boundary through the Ohio Valley and toward the southeast late Monday into Monday night. There may also be a secondary surface low developing off the mid Atlantic coast Monday night that helps to nudge a secondary boundary down through the region. Ahead of the boundary on Monday, axis of lower level theta-e air will be pivoting up into our region on increasing southwesterly flow and may lead to the development of some modest instability across the region. Recent CAM guidance does hint at the possibility of some shower activity developing Monday afternoon and into Monday night ahead of the secondary boundary. However, forecast soundings appear fairly capped above 800 mb, enough so that I`d prefer to leave our going dry forecast intact. Otherwise, with increasing southwesterly flow, temperatures should easily warm into the lower 80s and perhaps a touch warmer in the GA counties. Current forecast max temps are below record readings for February 27. Finally, deeper mixing will be able to tap stronger winds aloft with gusts of 18 to 25 knots becoming common during Monday afternoon. It will be close for Lake Wind Advisory criteria to be met on Lake Moultrie, and think gusts will remain largely under 25 knots. Thus, no headline at this juncture. Low amplitude mid level ridging and surface high pressure rebuild across the region for Tuesday through Wednesday and we should see a good amount of sunshine overall. Stretch of above normal temperatures will persist with highs in the lower to middle 80s for most areas, cooler along the coast. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... Larger scale flow pattern will be rather progressive through the midweek period with broad W/SW flow aloft, warm air entrenched across the Deep South, and an active storm track from the southern Plains into the Great Lakes. Early in the period, trailing frontal system is still looking to stretch out from the mid Atlantic into eastern Texas with some precipitation likely developing along the boundary....some of which may try to sneak into our area on Thursday/Thursday night. Heading into the latter half of the week and into the weekend, a stronger piece of short-wave energy will be digging a bit further into the southern CONUS, spinning a strong surface low that will pivot up through the Appalachian/Ohio Valley region on Friday and driving a strong cold front through the SE CONUS through Friday night. There remains a bit of uncertainty on the exact track of this system. But the system does have the potential to bring very gusty winds to our region (EURO/GFS peg 55-65 knots 1000 MB geostrophic winds across our area Friday and >80 knot 500 MB winds), possible marine and land based wind headlines, as well as the potential for severe weather. In fact, SPC Day 6 Outlook has our region in a 15 percent probability for severe storms. Will have to keep an eye on how this evolves as we go through the week. After FROPA, cooler weather returns heading into the weekend with readings heading back down to near normal for early March. && .AVIATION /03Z MONDAY THROUGH FRIDAY/... KCHS/KJZI: Low confidence on how fog and stratus will evolve overnight. Guidance is mixed in showing marine stratus gradually building down and transitioning to fog this evening and overnight, which could impact both terminals. Some of the more reliable near term guidance is favoring the foggier scenario and with marine stratus already noted just offshore per coastal webcams, the 00z TAFs will offer lower conditions compared to the previous 18z TAF cycle. Still favored a somewhat conservative solution limiting KCHS to MVFR with both vsbys/cigs dropping below alternate minimums at KJZI. It is very possible both terminals could drop to airfield minimums, especially at KJZI. Trends will be watched closely and amendments will be issued as needed. VFR should return to both terminals by mid- morning with gusty winds dominating from mid- morning through 00z Tuesday. KSAV: VFR. Risk for fog and stratus will remain well to the north of the terminal. Gusty winds will occur mid-morning through 00z Tuesday. Extended Aviation Outlook: Gusty southwest winds are anticipated across the region for Monday afternoon through Monday night, and a window of flight restrictions is possible at the terminals later Monday night into Tuesday as a weak front moves through the region. Periodic flight restrictions and gusty winds are possible again Thursday and Friday as a strong system rolls through the region. && .MARINE... Vsbys in the Charleston Harbor have tanked and reports from the Charleston Pilot Boat indicate the fog is slowly expanding offshore. A Marine Dense Fog Advisory has been issued until 9 AM for Charleston Harbor and the South Santee-Edisto Beach nearshore leg. Tonight: Areas of marine stratus could transition to areas of fog over parts of the South Santee-Edisto Beach Nearshore leg and Charleston Harbor later this evening and overnight. Confidence on how low vsbys will get remains low, but vsbys 1 NM or less are a possibility. A Marine Dense Fog Advisory could be needed. East to southeast winds will gradually transition to southwest overnight with speeds less than 10 kt. From Edisto Beach south over the remainder of the marine area, south to southwest winds will prevail with winds 10 kt or less. Seas will average 1-2 ft nearshore waters and 2-3 ft Georgia offshore waters. Monday: Gusty southwest winds develop across the coastal waters Monday afternoon through Monday night. Solid Small Craft Advisories are anticipated during this time but will hold off issuing Advisory headlines for now given it`s more than 24 hours out. However, some gale force gusts are possible across the Charleston nearshore waters Monday night and have opted to hoist a Gale Watch for that marine zone. Tuesday through Friday: Winds and waves diminish for Tuesday through midweek. But, winds and waves will be ramping up again for Thursday through the rest of the work week, with gale force gusts possible again on Friday. && .CLIMATE... A *preliminary* record high min as been set at KSAV with a low of 64 observed so far. The record high min for the date is 63 set in 1939. The record will not be officially set until after the climate day ends and official climate products, including the record report, is issued early Monday morning. Record High Temperatures: February 26: KCHS: 83/1996 KCXM: 80/1944 KSAV: 84/1996 February 27: KCHS: 84/1962 KCXM: 83/1962 KSAV: 86/2021 Record High Minimum Temperatures: February 28: KCHS: 63/2021 KCXM: 64/2017 KSAV: 66/2021 && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...Dense Fog Advisory until 9 AM EST Monday for AMZ330-350. Gale Watch from Monday evening through late Monday night for AMZ350. && $$
National Weather Service Hastings NE
509 PM CST Sun Feb 26 2023 ...AVIATION UPDATE... .DISCUSSION...(This evening through Sunday) Issued at 440 PM CST Sun Feb 26 2023 -- KEY MESSAGES FOR THE ENTIRE 7-DAY FORECAST: * By FAR the main forecast issue (and obviously the most imminent one) is our first official (albeit low-end) threat for a few strong/severe thunderstorms in 2023, with our main window of opportunity 6 PM-2 AM. SPC`s latest Day 1 outlook clearly focuses the official Marginal Risk near/especially south of the NE/KS border, but we are not discounting the possibility of a few stronger storms (with at least a small hail threat) farther north into our Nebraska counties. * Although not expected to be a significant/widespread concern, there appears to be a decent chance for a good chunk of especially the southeast half of our coverage area (CWA) to pick up a quick 0.25-0.50" rain tonight (localized higher possible/likely), which given the partially to mostly still- frozen soils, could lead to at least minor/nuisance flooding (a bit more than would normally see from fairly modest rain amounts). * As showers/storms vacate overnight, attention turns to strong northwest winds (gradient winds/non-convective) on the back side of the system. Although have very slightly toned-down our wind forecast from previous, a good chunk of Monday AM will likely feature widespread gusts of 40-50 MPH before winds gradually ease down during the afternoon. * Looking beyond these next 24 hours, a brief rundown of forecast highlights include: 1) outside chance for a shot of light rain and/or snow in our northern CWA Tuesday (not really in the official forecast at all presently)...2) The possibility (far from a sure thing!) of at least some light accumulating snow mainly during the Wed night-Thurs time frame. -- More details/further info building upon the Key Messages above (see short-term specific paragraphs farther below for details focused solely on the first 36 hours): 1) Changes worth noting from previous forecast (along with greatest uncertainties): - Honestly there have been truly "major" changes from the previous forecast package, both in the short/longer term periods. On the fairly minor side of things: 1) high temps nudged up very slightly for Monday...2) Snow chances (PoPs) Wed night-Thurs nudged up slightly (but still below "likely" percentages"), although latest deterministic model data would currently suggest that most of our CWA could easily stay dry/snow-free. 2) General overview of the large-scale/surface upper air pattern along with longer-term precip potential (and any key model differences): Honestly, the latest ECMWF/GFS and its associated numerical guidance are current in pretty remarkable throughout the ENTIRE 7-day, not only aloft but also at the surface in terms of frontal timing/temps etc. Briefly summarizing the 7-day situation: First the incoming vigorous shortwave/closed low plows across KS into MO/southern IA overnight (sparking our rain/storm chances). In it wake, we spend a few days in fairly broad/low amplitude quasi-zonal to slightly southwesterly flow, during which time we`ll have to watch for "sneaky" light precip chances (such as what especially the ECMWF suggests in our north Tues daytime). Then, the next primary larger scale shortwave trough approaches and eventually passes mainly to our south across OK/TX during the Wed night-Thurs time frame. Although this wave COULD produce some accumulating snow (mainly of the light variety) within our domain, the higher-confidence effect will be a one-day cool down (centered on Thursday). In the wake of that system, Friday appears to be a pretty high-confidence dry (and slightly warmer) day. Between Fri night-Saturday, another weaker trough is progged to cross the Central Plains out of the west-northwest, but at least for now, our forecast remains void of mentionable (15+ percent) PoPs given only weak/disorganized QPF signals. Finally, benign quasi-zonal flow returns by Sunday, which for being a full week out currently carries pretty high confidence in being dry and milder. 3) Brief temperature overview: As a whole, these next 7 days will average out slightly above normal (2 weeks out still showing decent signs of prevailing somewhat colder per ECMWF ensemble and latest CPC 8-14 Day outlook). But getting back to this upcoming week: Seasonably-mild Mon-Tues with highs mainly most areas 50s. A cool-down starts Wed with highs mainly 40s and then Thursday the outright-chilliest day with highs 30s and Thurs night lows teens. This colder snap is short-lived though as highs rebound well into the 40s Fri-Sat and then a decent signal for widespread 50s (some 60s south?) Sunday. --SHORTER TERM DETAILS FOCUSED SOLELY ON THE NEXT 36 HOURS/3 FORECAST PERIODS: - CURRENT RECENT/CONDITIONS SO FAR TODAY: At least for a short time longer, our CWA remains rain-free, as showers/storms are already erupting not far to our southwest in western KS. As expected, it`s been a seasonably-mild day (what an INCREDIBLE turn-around from 48 hours ago!), with highs on track to top out somewhere in the 50s most areas, with warmer 60s common along/south of the state line and even our extreme southwest corner (Rooks Co. area) flirting with 70. In the big picture, water vapor satellite and short term model data clearly depict a "powerhouse" trough churning east-northeast along the CO/NM border toward KS. At the surface, the associated low pressure center has deepened to around 990 millibars along the southern KS/CO border. In response to the pressure falls today, southeast winds have responded accordingly, currently averaging sustained 15-20 MPH/gusts 25+ MPH (likely 30+ far south). Skies have remained mostly sunny through the day, with low stratus skirting more to our east although high- level cirrus (including plentiful convective blowoff) will steadily continue invading from the west- southwest. - THIS EVENING-OVERNIGHT: The stage is set for a rainy (and in various places) stormy evening overnight. Although the very first showers/storms could enter our extreme southwestern CWA by 6 PM, the vast majority of "action" will focus between 6 PM-2 AM as widespread showers/embedded thunderstorms track across much of the CWA from west-southwest to east-northeast. On the large scale, the heart of the powerful mid level wave/closed low will track diagonally across KS from southwest-northeast overnight, reaching northern MO by 12Z/6AM. The associated surface low will follow suite, passing just over or barely south of our far southern CWA a few hours either side of midnight (around 985 millibars by then), and then exiting to northwest MO/southwest IA by 6 AM. With the main surface low and primary surface/low level instability axis passing to our south, our CWA is clearly not "ground zero" for a severe storm threat (and thus lies well north of the Enhanced/Moderate Risk areas to our south. That being said, with 0-1 kilometer CAPE up to around 500 J/kg expected to invade mainly our KS zones this evening (and higher elevated CAPE in the 850-700 millibar layer) perhaps up to 500-1000 J/kg up to roughly around I-80), there will be enough instability for at least limited severe. Surface based instability SHOULD remain weak enough (and nocturnal inhibition strong enough) to preclude a QLCS tornado threat in our south, but with very strong deep layer shear of 50+ knots and with at least a brief period of strong low level shear of 30-40+ KT, especially our KS zones (Marginal Risk area) will need watched for a damaging wind threat (60+ MPH), especially if the northern fringes of the MAIN squall line/linear complex surges into that area. Farther north, while most of our Nebraska CWA is not officially in the Marginal area, high-res models suggests enough aforementioned elevated CAPE that a sneaky nickel-quarter size hail threat COULD extend roughly as far north as I-80 if things come together just right. On top of actual convective concerns, we are at least modestly-concerned about localized, mainly minor flooding overnight. Although "official" QPF forecast call for the highest amounts to be only 0.25-0.50" and mainly in our southeast half, some of the latest HRRR/NAMNest runs are bit more concerning showing at least isolated stripes of 0.50-1.00" rain potential in parts of our south/east and maybe central. While this would normally not be of great concern during the warm season, the ground is still partially to mostly frozen (we only have around 1" of surface thaw here at our WFO this afternoon), so any heavier rain could run off fairly quickly. For sure, the main concern is brief/short term flooding of typical flood-prone areas, and we are less concerned about river flooding/ice jam flooding given the overall-modest train amounts and overall-low river levels. Something to keep an eye on though. ALL convection should vacate our far eastern CWA no later than 3-5 AM. In addition to the convective/possible hydro issues, northwest winds will start cranking up on the back-side of the departing low late in the night (especially after 3-4 AM). Typically-reliable higher res wind progs (such as from HRRR) suggest we SHOULD be "safe" from Warning criteria gusts of 58+ MPH, gusts of 40-50 MPH are certainly likely. Lastly, and on the more mundane side, low temps overnight should bottom out in the mid-upper 30s most areas (perhaps holding up around 40 far southeast). - MONDAY DAYTIME: Aloft, the big trough will rapidly continue its eastward departure, centered over the OH area by 00Z/6PM while the associated surface low reaches southern MI. Locally, by far the main story Monday will be fairly strong northwest winds, particularly during the morning hours as the pressure gradient remains tight on the backside of the departing low and diurnal mixing at least partially taps into very strong low-level winds for a time. Fortunately, models do not show full/efficient deep mixing or we might be talking Warning level winds. Even so, the entire CWA can expect sustained speeds of mainly 25-35 MPH/gusts 40-50 MPH for at least a few hours Monday morning. Fortunately, winds will gradually back off in the afternoon, with late afternoon/early evening sustained speeds only 10-20 MPH/gusts 15-25 MPH. Unless some lower clouds linger a bit in east-northeast zones for a time, skies should be sunny/mostly sunny. Nudged up high temps 1-2 degree most areas, ranging from around 50 far north to low 60s in KS zones (mid 50s Tri Cities). Fortunately relative humidity levels should hold up far enough to preclude fire weather issues (along with the recent rainfall), but will need to watch especially Rooks Co. in our far southwest for perhaps a few hours of near-critical fire weather. - MONDAY NIGHT: High confidence dry, although mid-high level clouds will gradually increase into especially our northern half (mainly post-midnight) as a weak disturbance approaches from the west-southwest. Once the late afternoon-early afternoon breezes subside, most of the night will only feature winds of 5-10 MPH, gradually turning from northerly to easterly. Not currently a strong signal for fog issues, but this will bear watching, especially in places where ground remains wet from tonight`s rain. Low temps were changed very little, mainly mid-upper 20s most areas. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Tuesday) Issued at 508 PM CST Sun Feb 26 2023 Precipitation over NW KS will move into the TAF sites this evening. Currently thinking SHRA, but there is a small chance for VCTS this evening also. I TEMPO`d lower ceilings and vis with heavier showers, but that could change if a TSRA moves into the TAF sites. Ceilings are forecast to go IFR this evening and the HRRR drops vis to IFR also so figure a TEMPO should cover those conditions initially. The winds will shift from SE to NW tonight and gusty winds and LLWS are likely behind the SFC low. The winds will slowly taper off tomorrow and by evening will be NW 10-15kts. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ DISCUSSION...Pfannkuch AVIATION...Beda
Area Forecast Discussion
National Weather Service Grand Rapids MI
957 PM EST Sun Feb 26 2023 LATEST UPDATE... Update .UPDATE... Issued at 939 PM EST Sun Feb 26 2023 The ongoing forecast looks good with no significant changes made. A large area of moderate to heavy precipitation was developing in eastern NE southward into KS. This was associated with the developing surface wave in central KS. This feature deepens as it tracks northeast tonight into Monday...expanding the precipitation as is approaches MI. Surface temperatures were below freezing across the CWA. The surface temperatures are predicted to climb slowly Monday morning as the precipitation moves in. It still looks like by the time the precipitation reaches Kalamazoo and Battle Creek...surface temperatures should be a few degrees above freezing based off the latest guidance. As a result we will not expand the WSW further south at this time. However...we will need to monitor the trends through the remainder of the night as it will be a close call for possible impacts for the Interstate 94 corridor Monday morning. Further north for the Muskegon to Grand Rapids to Lansing area...there will be a delay in when the surface temperatures climb above freezing so it does look like impacts will occur from the freezing rain...starting up Monday morning. Northeast of Grand Rapids it may stay below freezing for most of the day on Monday. Thus the impacts will last there longer and they will be more widespread. However that region may see sleet and snow mixing in at times which would limit the freezing rain accretion duration. Still more than a quarter inch of freezing rain is possible in that region. && .DISCUSSION...(This evening through next Sunday) Issued at 258 PM EST Sun Feb 26 2023 - Wintry Mix for Monday - Tranquil weather tonight is followed by the leading edge of mixed precip moving from southwest to northeast on Monday morning. The Winter Weather Advisory issued early this morning follows the timing and precip type forecast from a blend of the HRRR and global models which have slowly converged towards a solution that has shifted the axis of heavier freezing rain, on the order of two tenths of an inch or more, to the north central and northwest forecast area, with more sleet and snow and less icing across the northeast. An occluded low combines with a retreating cold high to set up a period of overrunning warm air and surface cold advection on easterly winds during the morning that will give a brief period of icing along and just south of I-96. A short duration advisory will cover that threat from Allegan to Ingham Counties. This area will be dry-slotted and warm above freezing after the initial burst of mixed precip. Further north, the threat will persist longer with the dry slot lifting to the northern zones by late afternoon, but wraparound showers of mixed precip persisting into the evening across the far northeast where 2 to 5 inches of snow along with some sleet and freezing drizzle are possible for Osceola and Clare Counties. South of I-96 we expect mostly rain with close to an inch of QPF. This will cause some rises on local rivers and streams but at this point we do not expect river flooding. The DGZ loses saturation after 00Z so only light precip is expected during the evening and impacts from any freezing drizzle will be mitigated by the coating of what fell previously. - Light snow or mix for Wednesday, colder end of the week - A weak low pushes an area of f-gen across Lower Michigan on Wednesday with some rain or snow, but marginal surface temperatures should mean travel impacts will be minimal. A couple inches of snow accumulation are possible in any persistent f-gen forced mesoscale bands. Colder weather follows for the end of the week and we will have to watch the southern stream low tracking across the Ohio Valley on Friday. The GFS is currently a northern outlier and brings significant snow to our forecast area while the ECMWF and Canadian remain further south but the northern edge of the precip shield clips SE Lower Michigan. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 630 PM EST Sun Feb 26 2023 A storm system will track into the TAF sites Monday morning bringing a variety of hazards to the TAF sites. The thermal profile supports a wintry mix in the morning...but as the warmer air continues to advect in...the sites will transition to rain for the afternoon. Wind shear will also be possible especially Monday morning. A strengthening low level jet tracks in from the south and will likely top 50 knots. This feature combined with the lower surface wind speeds will generate the hazardous conditions. IFR and lower conditions will spread in during the morning...and persist into the afternoon. How quickly those conditions develop is a little uncertain as the low levels will initially be dry as the precipitation moves in. && .MARINE... Issued at 225 PM EST Sun Feb 26 2023 Gale Warning for Monday with east gales to 35 knots. There will be a period of west winds to 30 knots in the cold advection on the back side of the departing low Monday night into Tuesday, so a Small Craft Advisory will be needed for that period. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...Winter Weather Advisory from 9 AM to 5 PM EST Monday for MIZ037- 043-050. Winter Weather Advisory from 9 AM to 8 PM EST Monday for MIZ038- 044>046-051-052. Winter Weather Advisory from 9 AM to 10 PM EST Monday for MIZ039- 040. Winter Weather Advisory from 7 AM to 3 PM EST Monday for MIZ056>059. Winter Weather Advisory from 7 AM to noon EST Monday for MIZ064>067. LM...Gale Warning from 5 AM to 4 PM EST Monday for LMZ844>849. && $$ UPDATE...MJS DISCUSSION...Ostuno AVIATION...MJS MARINE...Ostuno
Area Forecast Discussion
National Weather Service Gray ME
756 PM EST Sun Feb 26 2023 .SYNOPSIS... High pressure builds later tonight and Monday followed by a complex system bringing snow to the region Monday night through Tuesday. Another brief area of high pressure crosses Wednesday followed by a broad area of low pressure that will bring mountain snow, and rain or snow south of the mountains Thursday. Behind this system will be another brief period of high pressure Friday with potential for another system to track near the East Coast next weekend. && .NEAR TERM /THROUGH TONIGHT/... 750 PM...A band of more robust snow showers moving through SE NH and southern York county should be offshore in the next hour. this could produce a quick coating of snow. Otherwise fairly clear should persist outside of the mtns and in srn NH overnight. Temps may rise a few degrees with front pushing through but will fall again after midnight, so no significant changes. Previously...Light snowfall is expected to gradually wind down with not much in the way of additional accums into early this evening across most of the area. However, locations just east of a Lewiston to Brunswick line and toward the Midcoast could see an inch or so of snow could occur over the next couple hours, but potential seems to be diminishing as the latest volume scans from GYX are showing a weakening trend in the reflectivity. Will also keep a low-end chance of snow showers a little longer into the evening across NH and southwestern ME as the HRRR and NAMnest continue to suggest this as a possibility. Otherwise, a dry north to northwest flow will take over this evening and tonight as the low pressure and front continue to exit to the east. This will end the snow shower potential for most, except for the upslope snow showers toward and in the mountains. However, these will also lessen in coverage during the nighttime hours. Cloud cover will also gradually diminish south of the mountains overnight, so temperatures should be able to fall pretty quickly once enough clearing occurs. Forecast lows are generally in the single digits, except some teens across the south and along the coast. However, the normally colder spots could approach zero. && .SHORT TERM /MONDAY AND MONDAY NIGHT/... Broad high pressure builds in for Monday resulting in a dry day with partly sunny skies, with clouds starting to increase in the late afternoon or early evening hours ahead of our next storm system. Max temps are expected to reach the mid to upper 20s for most of the region and near 30 degrees across southern NH. Going into the evening and nighttime hours, a complex low pressure system will quickly moves across the Great Lakes and Ohio Valley regions toward the Northeastern U.S, which is expected bring another round of accumulating snow to the area. There will be some dry air aloft to overcome initially, but with the column continuing to moisten steadily increasing isentropic lift across the area, light snow is expected to overspread the region from south to north from late Monday evening into the overnight hours. Based on latest guidance, snow should start reaching the surface across southern NH give or take an hour or two either side of midnight, and then slowly expanding to the north and east across central/northern NH and western ME through the course of the night. With a couple of inches possible during the overnight hours and light snow expected to be ongoing as we approach daybreak, a slick morning commute is certainly possible. More details below. && .LONG TERM /TUESDAY THROUGH SUNDAY/... Busy pattern continues with several short wave troughs moving across or at least near the region this coming week into the weekend. The long term period starts off with what looks like a snowy Tuesday for most, and a winter storm watch has been posted for zones that at this time appear most likely to achieve 6"+ snow accums. The bulk of the watch is across Maine, and this is where several models have slightly better forcing for ascent due to a low level trough and frontogenetic zone as the approaching short wave trough "tugs" on well-offshore low pressure. Some ocean enhancement may occur as well. The precipitation tapers off and ends after midnight Tuesday night as the short wave trough passes through. Both commutes on Tuesday will be affected by slippery conditions. The weather pattern remains busy as Midweek may bring another significant precip producing system centered around Thursday. This one, at least initially, looks a bit warmer so mixed precipitation types will probably come more into play with this next one. There will be a really short break before the next short wave trough approaches, which could bring another wintry system Friday and/or Saturday. && .AVIATION /01Z MONDAY THROUGH FRIDAY/... Short Term...Light to occasionally moderate snow will continue the possibility of MVFR ceilings with visibilities ranging from IFR to MVFR. Precipitation will gradually wind down with visibilities improving later this afternoon into this evening. Ceilings may take a little longer to improve, but most sites should return to VFR by late this evening. VFR expected at all sites during the day Monday. Light snow will then overspread New England from south to north Monday evening and Monday night resulting in IFR visibilities and MVFR to IFR ceilings. Long Term...IFR conditions are expected for much of the day Tuesday in snow. Conditions improve to VFR Wednesday before another system impacts the region Thursday with potential for MVFR to IFR conditions in RA and/or SN starting Wednesday night. && .MARINE... Short Term...Weak low pressure moves across the waters this afternoon into tonight bringing a round SCA conditions through tonight. Conditions improve Monday as high pressure builds in, but a low pressure moving off the Mid-Atlantic will bring increasing easterly winds and deteriorating conditions Monday night. Long Term...Low pressure passing south of the waters Tuesday will bring increasing easterly flow and seas building to around 10 ft. Easterly winds will bring at least SCA conditions with potential for a period of Gales along the outer waters. Winds drop below SCA thresholds Tuesday night into Wednesday while elevated seas likely bring SCA conditions through Thursday. An increase in winds is likely on Friday. && MONDAY .GYX WATCHES/WARNINGS/ADVISORIES... ME...Winter Storm Watch from late Monday night through Wednesday morning for MEZ012>014-018>028-033. NH...Winter Storm Watch from late Monday night through Wednesday morning for NHZ004-006-008>010-015. MARINE...Small Craft Advisory until 9 AM EST Monday for ANZ150-152. Small Craft Advisory until 10 PM EST this evening for ANZ154. && $$ NEAR TERM...Cempa/Combs SHORT TERM...Combs LONG TERM...Ekster
Area Forecast Discussion
National Weather Service Hanford CA
232 PM PST Sun Feb 26 2023 .SYNOPSIS...The first in another series of storm systems will begin to impact the region late this afternoon. Rain, mountain snow, and gusty winds will continue at times through Wednesday. Dry weather is forecast on Thursday and Friday but freezing temperatures are likely across much of the San Joaquin Valley both mornings. && .DISCUSSION... The next storm system set to impact central California continues to drop south out of the Gulf of Alaska. Warming and some peeks of sun ahead of this approaching low pressure system are providing us with temperatures this afternoon around 6 to 9 degrees higher than yesterday`s cold and cloudy/rainy conditions. An area of precipitation sliding southward ahead of the approaching upper low is consolidating into a band about 70 miles to the north of our area and will will begin to move into our area by around 4 PM. HRRR model pushes this band through central California overnight, bringing around one tenth of an inch or less of additional rainfall to the west side of the San Joaquin Valley and as much as three to four tenths of an inch on the east side. Snow levels are progged around 2000 to 3000 ft overnight, above which several inches of additional snow will accumulate, up to around 18 inches in the higher elevations. A Winter Storm Warning is in effect for the Sierra Nevada and foothills beginning at 4 PM. The precipitation will begin impacting the Kern County mountains by early Monday morning. Snow levels are progged to be at or below the elevation of the major highway passes again, and accumulating snow is expected to bring additional travel disruptions. A Winter Storm Warning is in effect for the Kern County mountains beginning at 4 AM Monday morning. As the upper low swings inland Monday morning, the trough will push into the California coast, and another round of precipitation will move into central California. This will bring similar amounts of rainfall in the San Joaquin Valley through Tuesday morning along with around 2 feet of additional snow in the higher elevations of the Sierra. Increased winds will accompany the passing trough and create blowing snow impacts. A Blizzard Warning will therefore be in effect for the higher Sierra beginning 10 AM Monday morning. Winds are projected to gust up to 25-30 mph in the San Joaquin Valley Monday, which could be enough to topple some shallow rooted trees in saturated soils. A third wave of precipitation Tuesday into Wednesday will bring around one Quarter to one half inch of additional rainfall to the Valley and up to 3 to 4 more feet of snow over the high Sierra. Low snow levels continue through the period and the Winter Storm Warnings continue for the Kern County Mountains and the Sierra foothills through 4 PM Wednesday, in addition to the Blizzard Warning for the higher Sierra Nevada. Model ensemble solutions indicate a drier northwesterly flow by Thursday and Friday behind the exiting systems, then another winter storm system dropping into he region by Sunday. Blended model guidance predicts overnight low temperatures will drop to around the freezing mark in the San Joaquin Valley, with around a 75 to 95 percent chance of low temperatures at or below 32 degrees early Thursday morning. && .AVIATION...Mountain obscuring IFR conditions with precipitation spreading north to south after 00Z Monday. Local MVFR/IFR in rain across the San Joaquin Valley after 00Z Monday. Elsewhere VFR conditions will prevail across the central CA interior for the next 24 hours. && .AIR QUALITY ISSUES... On Monday February 27 2023, Fireplace/Wood Stove Burning Status is: No Burning Unless Registered in Fresno and Madera Counties. Burning Discouraged in Kern, Kings, Merced, and Tulare Counties, and Kern (Greater Frazier Park Area) and Sequoia National Park and Forest. && .CERTAINTY... The level of certainty for days 1 and 2 is medium. The level of certainty for days 3 through 7 is medium. Certainty levels include low...medium...and high. Please visit for additional information and/or to provide feedback. && .HNX WATCHES/WARNINGS/ADVISORIES... Winter Storm Warning from 4 PM this afternoon to 4 PM PST Wednesday for CAZ318-320-322. Winter Storm Warning from 4 PM this afternoon to 10 AM PST Monday for CAZ323>331. Blizzard Warning from 10 AM Monday to 4 PM PST Wednesday for CAZ323>331. Winter Storm Warning from 4 AM Monday to 10 PM PST Wednesday for CAZ332>336. && $$ public...JEB aviation....JEB
Area Forecast Discussion
National Weather Service Indianapolis IN
1003 PM EST Sun Feb 26 2023 .Forecast Update... Issued at 957 PM EST Sun Feb 26 2023 The forecast remains on track with only minor adjustments made to match observations. Current surface analysis shows a strong low near the central plains and a weak high across the Mid-Atlantic. This low will move towards the Great Lakes Region and lead to a tightening pressure gradient late tonight into Monday. Expect winds to begin increasing overnight as a result. GOES16 shows a large area of high clouds associated with this system already streaming into central Indiana. Clouds will continue to increase in coverage and rain will begin later tonight as a warm front lifts north. && .Short Term...(This evening through Monday) Issued at 220 PM EST Sun Feb 26 2023 - Wind Advisory Monday; Gusts to 50 MPH possible. - Rain expected on Monday; Thunderstorms possible. Surface analysis early this afternoon shows a large area of high pressure in place from the deep south, across Indiana to the Great Lakes and Ontario. Aloft, water vapor showed deep low pressure over the American southwest (which will become a big player in our weather on Monday), with ridging building across the plains states. This was resulting in lee side subsidence across the Ohio Valley. A tropical plume of moisture was streaming across TX within the ridge and extended toward the Ohio and Tennessee River Valleys. GOES16 shows high clouds associated with this plume streaming across the southern half of Indiana. Dew points across the area were in the lower to mid 30s. Tonight... Increasing clouds will be expected tonight, with scattered rain showers developing late. The previously discussed upper low across the southwestern states is expected to make quick progress across the plains toward Illinois overnight. Initially this evening the ridging aloft to the west is expected to continue to build across Indiana and the Ohio Valley leading to continued subsidence along with warm air advection through the overnight period. However, As the upper low pushes across the plains, associated surface cyclogenesis is expected to occur over Kansas. The 295K Isentropic surface shows the arrival of strong isentropic lift over Indiana ahead of the approaching low, with specific humidities over 8 g/kg. Forecast soundings suggest a gradual saturation through the night with a saturated column arriving near 12Z and pwats over 1 inch. Given the flow of the tropical plume arriving in the Ohio Valley, this should result in increasing clouds along with the development of showers late as the column becomes saturated as the forcing dynamics increase with the approach of the Low pressure system from the west. HRRR suggest showers arriving from the southwest late tonight within the isentropic lift. Thus will continue with a dry forecast this evening, but increasing pops overnight especially after 09Z. Given the ongoing warm air advection, expect steady or slowly rising temps overnight. Lows temps within the 12 hour tonight period will be achieved during the evening prior to the arrival cloud cover and warm air advection as temps in the lower 50s will be common by sunrise on Monday. Monday... An active weather day is in store on Monday. The previously mentioned surface low is expected to track across northern Illinois to Michigan through the day, deepening all the way. The past of this system will keep Central Indiana within the warm sector. Due to the deepening low, a strong low level jet is expected to pass across Central Indiana with speeds in excess of 60 knots at 850mb. As expected, the surface pressure gradient is sharp. Aloft, the associated upper system also is expected to push across Indiana through the day becoming negatively tilted through the process. These features will result in favorable forcing dynamics as forecast soundings remain deeply saturated though much of the day and pwats remain over 1 inch. Forecasts soundings fail to show much in the way of instability, and remain mainly saturated moist adiabatic. Given the favorable forcing and moisture along with an approaching surface cold front associated with the system, showers and perhaps a thunderstorm will be expected. Due to the strong winds aloft and the strong pressure gradient, any downburst could allow some of the stronger winds aloft to mix downward. Thus for now the ongoing wind advisory will continue as a windy day with high gusts appears reasonable. Gusts on Monday could reach near 50 mph, causing tree damage and possible power outages, and damage to unsecured objects. Will use categorical pops, but given the expected clouds and rain will try to keep highs contained to the lower 60s. && .Long Term...(Monday night through Sunday) Issued at 220 PM EST Sun Feb 26 2023 Tuesday and Wednesday... Much quieter weather will ensue for the beginning of the Long Term as weak high pressure builds in a modest CAA regime Monday night. Any cold air intrusion will be brief as the Ohio Valley remains in generally S-SW flow with broad troughing over the Inter- Mountain West. A weak shortwave looks to develop along a mid level jet Tuesday night that will further reinforce this southerly flow, pushing temperatures well above normal by mid-week. Cannot rule out light rain showers on Wednesday within a corridor of isentropic lift and moisture return, but greatest QPF should remain south within stronger dynamics as a secondary low develops over the Mississippi Valley. Thursday through Saturday... The main focus on the long term will be on the impending development of a deep low pressure system late next week. Currently, this lobe of energy is over the northern Pacific, but will traverse down the Western Coast, eventually entering a favorable cyclogenesis environment over the desert SW. After which ensemble member are widely varied on low track, but are fairly consistent on deep cyclogenesis somewhere over the Great Lakes/Ohio Valley region. Current thoughts are for this system to gradually trend northward as snow depth to the north and mid week warmth help develop a quasi-baroclinic zone, but many potential solutions, including snow are still in play. One feature to keep an eye on will be the placement of a potential surface high over Ontario. The push of CAA along the CCB will greatly impact the temperature gradient north of the warm front, and if this high continues to trend eastward, less cold air could lead to above freezing temperatures and therefor a cold rain instead of snow. Still enough possibilities remain for an impactful winter event, and should be closely monitored in the coming days. && .Aviation...(00Z TAF Issuance) Issued at 635 PM EST Sun Feb 26 2023 Impacts: * VFR Conditions until late tonight. * Lowering ceilings to MVFR and IFR arriving overnight with rain * Strong winds start early Monday with LLWS Discussion: High pressure across the region will continue to provide VFR conditions this evening. Late tonight, a strong area of low pressure will begin to advance toward Indiana from the plains. Ceilings will lower quickly with MVFR ceilings expected at all sites by 05-07Z and becoming IFR shortly after that. Some locations could see brief LIFR conditions late tonight into tomorrow morning as showers and storms move through. Furthermore, a strong pressure gradient is expected to be present as the deep upper low and associated surface low pass. Models show a 60- 65 kt low-level jet developing which will result in LLWS tomorrow as the surface low passes due to both speed and direction. && .IND WATCHES/WARNINGS/ADVISORIES... Wind Advisory from 7 AM to 7 PM EST Monday for INZ021-028>031- 035>049-051>057-060>065-067>072. && $$ Update...Melo Short Term...Puma Long Term...Updike Aviation...Melo
Area Forecast Discussion
National Weather Service Midland/Odessa TX
514 PM CST Sun Feb 26 2023 ...New AVIATION... .SHORT TERM... (This afternoon through Monday night) Issued at 120 PM CST Sun Feb 26 2023 * Significant Windstorm Expected This Afternoon and Evening An active afternoon and evening is ahead for Southeast New Mexico and West Texas, as a potent trough and its attendant jet move over the region. The aforementioned trough is currently located near the AZ/NM state line, and per latest satellite imagery and RAP analysis is beginning to develop a subtle negative tilt. Clouds from this morning continue to clear from west to east, with a stout low-level jet resulting in gusty southerly to southeasterly winds across the Trans Pecos and Permian Basin, with southwesterly winds overspreading western areas in association with a pre-frontal trough. The gusty winds we see right now are likely the lightest winds we`ll see until after midnight tonight, as the trough translates east-northeastward, dragging an anomalously strong Pacific front (for this time of year) through the region. This front will produce a sharp westerly wind shift, with widespread wind gusts expected to reach 50-70mph across the lower elevations, and up to 95- 105mph across the Davis, Guadalupe, and Delaware Mountains. Current satellite imagery also indicates a swath of blowing dust advecting northeastward out of northern Chihuahua, MX, and this dust will overspread the region this afternoon and evening, with widespread blowing dust expected and localized significant visibility reductions possible, especially along the Pacific front as it moves through the area. In addition to the winds and dust, thunderstorms will also be possible late this afternoon and early evening, mainly across the eastern Permian Basin. Storms that develop would likely be high- based to start with, with significant downward momentum yielding an enhanced wind threat, though brief rainfall and large hail would be possible. Storm motion would likely be upwards of 60kt to the east- northeast, with greater potential for strong to severe thunderstorms expected over the Rolling Plains northeastward into western and central Oklahoma. One other variable this afternoon into this evening is also widespread elevated fire weather conditions across Southeast New Mexico and West Texas, with concern for fire starts due to potential downed power poles/arcing power lines, as well as lightning strikes over eastern areas. Any fires that begin could spread quickly in the dry and windy conditions, and more on the fire threat can be found in the Fire Weather Discussion below. As the Pacific front moves east of the region tonight, cooler and drier air will filter into the region, with winds gradually diminishing as the gradient slackens and with a loss of mixing. Continued westerly flow will will maintain mild overnight temperatures with lows in the 30s and 40s. While winds will diminish overnight, high winds will persist across the mountains, where the High Wind Warning remains in effect through Monday evening. In a post-frontal regime, highs Monday will top out cooler than today, but still above normal for late February, in the middle 60s and lower 70s for most. Monday evening, relief (albeit, brief) from the high winds will arrive in the Guadalupe and Delaware Mountains as winds diminish with the departure of the midlevel jet. Lows will once again drop into the middle 30s and 40s for most, with the light winds making for a pleasant night. && .LONG TERM... (Monday through Saturday) Issued at 120 PM CST Sun Feb 26 2023 * Another high wind event forecast for west Texas and southeastern New Mexico Thursday... We will see a short period of short wave ridging before yet another potent upper level system reloads over the desert southwest and approaches west Texas and southeastern New Mexico Wednesday and Thursday. Prototype cluster analyses of 500 hPa ensemble height anomalies suggests to me to have two mode where the system is slower in translating eastward over the desert southwest and maintains closure whereas the second mode is more progressive and opens the low into a wave over the southern Rockies. Since the trend has been for systems to beat themselves against a persistent southeastern US ridge and that the massively negative NAO doesn`t seem to go anywhere anytime soon per ECMWF and GEFS ensembles, we`ll stick with the more open solution, keeping the bulk of precipitation (such as it will be) north of the Permian Basin Wednesday night into early Thursday. Thursday appears to be another windbag event, with the ECMWF Extreme Forecast Index and SoT looking pretty gnarly. While not as significant as the ongoing windbag event, wind gusts near hurricane strength are likely over the Delaware/Guadalupe ranges with high wind warning criteria met or exceeded across much of the adjacent plains. And after that system passes, we`ll see some quasizonal flow through next weekend. Meaning things should get a little quieter for awhile. Don`t count on it lasting, though. Regrading sensible weather, highs Tuesday and Wednesday will be about 10 degrees above normal under southwesterly flow aloft. Would be warmer but there could be extensive cirrus near us ahead of this system. May see some showers across southeastern New Mexico and the northern Permian Basin late Tuesday/early Wednesday but QPF will be scant. Then another Pacific front plows through the region Thursday morning, dropping highs to slightly below early March normals. Winds should subside Thursday evening, and with lighter winds and very good radiational cooling expected, lows Friday morning will be a bit on the nippy side, ranging from the lower 20s near Tatum, NM to the mid 30s along the Rio Grande. From there, temperatures trend to near normal with no precipitation expected. bc && .AVIATION... (00Z TAFS) Issued at 454 PM CST Sun Feb 26 2023 Very strong southwest winds are overspreading all terminals with the strongest winds at the western most terminals. Gusts up to 50-60 kts are possible through the early evening. As the highest winds initially hit, blowing dust may drop visibility to IFR. Visibilities will slowly recover after initially falling. Winds begin to decrease, becoming westerly, after sunset but remain strong. Winds decrease further after midnight. && .FIRE WEATHER... Issued at 341 PM CST Sun Feb 26 2023 * At request of local officials have issued a Red Flag Warning for Southeast New Mexico until 8 PM MST. * Elevated fire weather conditions expected all week... The ongoing high wind event will make for IA concerns in any ignition this afternoon and evening with ERCs at or below the 50th percentile. There will be some RH recovery overnight, mitigating concerns some, but Monday looks to be another breezy day, especially from southeastern New Mexico south to the Big Bend. Drying continues Tuesday with winds a bit stronger. Wednesday and Thursday look to be the windiest days, but RH recovery will be better and therefore fine fuels may bounce back a bit before the Pacific front slams the area. IA concerns, however, will be present all week. Obligatory PSA: emphasize to people to not be buttheads and keep those lit cigarettes in their vehicles, not carelessly tossed out onto fuels which could start a wildland fire. Also check to see that those hauling trailers are not dragging chains, and for folks to avoid activities which may generate sparks like welding or trash burning or parking running vehicles in tall grass. && .PRELIMINARY POINT TEMPS/POPS... Big Spring 39 72 41 77 / 10 0 0 0 Carlsbad 34 70 40 71 / 0 0 0 0 Dryden 46 82 46 85 / 0 0 0 0 Fort Stockton 42 75 43 81 / 0 0 0 0 Guadalupe Pass 35 59 40 63 / 0 0 0 0 Hobbs 31 67 39 70 / 0 0 0 0 Marfa 33 68 35 76 / 0 0 0 0 Midland Intl Airport 38 72 42 76 / 0 0 0 0 Odessa 39 72 44 76 / 0 0 0 0 Wink 36 72 39 77 / 0 0 0 0 && .MAF WATCHES/WARNINGS/ADVISORIES... TX...High Wind Warning until 10 PM CST /9 PM MST/ Monday for Davis Mountains-Guadalupe Mountains Above 7000 Feet-Guadalupe and Delaware Mountains. High Wind Warning until midnight CST tonight for Andrews-Borden- Central Brewster County-Chinati Mountains-Chisos Basin- Crane-Davis Mountains Foothills-Dawson-Eastern Culberson County-Ector-Gaines-Howard-Loving-Lower Brewster County- Marfa Plateau-Martin-Midland-Pecos-Presidio Valley-Reeves County Plains-Scurry-Van Horn and Highway 54 Corridor-Ward- Winkler. Wind Advisory until midnight CST tonight for Glasscock-Mitchell- Reagan-Terrell-Upton. NM...Red Flag Warning until 8 PM MST this evening for Chaves Plains- Eddy Plains-Lea-Sacramento Foothills and Guadalupe Mountains. High Wind Warning until 9 PM MST Monday for Guadalupe Mountains of Eddy County. High Wind Warning until 11 PM MST this evening for Central Lea County-Eddy County Plains-Northern Lea County-Southern Lea County. && $$ SHORT TERM...84 LONG TERM....72 AVIATION...91
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
932 PM CST Sun Feb 26 2023 .UPDATE... Issued at 918 PM CST Sun Feb 26 2023 We just finished up a pretty sizable update to the forecast to incorporate the latest trends that we are seeing from the early arriving 00z guidance (so CAM heavy at this point). Main story here is this continued the trend the previous discussion mentioned of an eastward shift in the heaviest precipitation. This resulted in a roughly 25% reduction in QPF across the board, even where the heaviest precip is still expected in western WI. In addition, this update keeps temps up in the mid 30s in western WI through the afternoon, which also took a further hit out of the snowfall forecast there, though the p-type in western WI continues in the afternoon continues to sit on a knifes edge to falling as more snow or more rain. After all of these updates, we did end up dropping a few more counties from the advisory in MN. Douglas and Pope were dropped as precip is looking unlikely to make it that far west and Kandiyohi, Meeker, and Wright where the combination of less QPF and warmer temps greatly reduced the icing forecast. In the metro, left Anoka and Washington counties in the Advisory, though it`s the northern, exurban areas of those counties that look to have the potential for icing conditions. && .DISCUSSION...(This evening through Sunday) Issued at 310 PM CST Sun Feb 26 2023 KEY MESSAGES: - Freezing rain and significant icing expected across most of western Wisconsin late tonight and early Monday. - Model consistency for impacts on the western edge of Monday`s system remains very poor, but confidence is slowly beginning to improve. - Another round of light snow likely Tuesday night and Wednesday. A vigorous and compact upper low over the southern Rockies will begin to turn east northeast toward the mid Mississippi Valley tonight as it encounters the strong mid level ridge over the southeast. The trend today reversed yesterday`s trend by shifting the storm back to the east. It seems most of the guidance is beginning to converge on this idea with the 18Z NAM more in line with the 12Z GFS and ECMWF. There is very little time left for any more large swings, so confidence is increasing. The NBM forecast for this afternoon is based primarily off of last night`s model runs, so some significant manual edits were necessary to tamp down that solution in favor of the current trend. There will need to be more work done this evening to further refine QPF and resultant snow and ice accumulations. This is especially true across east central Minnesota and northwest Wisconsin where QPF may end up about half of what is currently forecasted. Confidence remains high enough to maintain the entire Winter Storm Warning in Wisconsin. No changes to headline type was made, aside from dropping the advisory across parts of far western Minnesota due to the drier solution. Precipitation will lift north rapidly late tonight, engulfing southern/eastern MN and WI by early Monday morning. Very warm air aloft will ensure no snow, and it should melt all hydrometeors completely to make sleet difficult to achieve too. What`s left is a surface temperature forecast hovering around freezing to determine if precipitation falls as plain rain or freezing rain. With a breezy east-southeasterly flow mostly originating from the current chilly airmass in place, not expecting temperatures to rise above freezing before precipitation begins across central MN and western WI. There may be a period of several hours freezing rain is occurring as precipitation rates increase into early Monday morning. This aspect of the forecast has remained pretty consistent and forecast ice grids remain near 1/4 inch across most of west central WI. By late Monday morning, temperatures should rise to the warm side of freezing and end any further icing threat. By afternoon, the back edge of precipitation will clear from southwest to northeast and could mix with a little light snow before ending. With temps still above freezing, snow accumulation will remain light. Quick on the heels of the early week system, another will track east into the northern Plains Tuesday into Wednesday. This one won`t have as much moisture to work with and a narrower band of precipitation is likely on its northern half. Frontogenetic bands tend to shift north and south and there has been little consistency with the track, so confidence remains low. The system could still drop a few inches of snow anywhere across the Dakotas, Minnesota, and northern Wisconsin. PoPs remain relatively low for now until greater consistency develops, but some likelies are now in place across central MN. High pressure builds in for the rest of the period and another shot of colder air will return late week. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 600 PM CST Sun Feb 26 2023 As noted in the main discussion, we continue to see western MN dry out, to the point now where we kept the AXN TAF dry, with the back end of the precip shield expected to be within 20 miles east or west of RWF. With the HRRR bringing the precip shield just west of RWF, did keep -RA mention going there. CIGS are expected to drop pretty quick to between 400 and 800 feet as the precip moves in. Through 15z, the warm nose looks strong enough to keep p-types all liquid. Between 15z and 18z this warm nose collapses, with the surface temps driving a type of fzra/ra to determining whether it`s rain or snow by 18z. -FZRA is still expected to be the predominate p-type at STC, with RNH/EAU warming above freezing and transitioning to -RA around 15z/16z. As the precipitation is ending, -SN chances increases, especially at STC, but for MSP/RNH/EAU, temps are currently forecast to stay too warm while precip is still in place in the afternoon to drive much of a -SN threat. KMSP...Some brief periods of -fzra are possible between 6z and 9z, but by the time the main precip shield gets to MSP between 9z and 10z, it will be warm enough to keep this as a cold rain. For the last 6 hours of the TAF, it becomes a question of how quickly does the stratus clear out. Right now, that looks to happen between 2z and 5z. /OUTLOOK FOR KMSP/ Tue...VFR. Wind W 5-10 kts. Wed...MVFR likely. Chc IFR/-SN. Wind NE 10-20 kts. Thu...VFR. Wind N 5-10 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...Winter Weather Advisory from 3 AM to 3 PM CST Monday for Benton- Chisago-Isanti-Kanabec-Mille Lacs-Morrison-Stearns-Todd. Winter Weather Advisory from 3 AM to 10 AM CST Monday for Anoka- Sherburne-Washington. WI...Winter Weather Advisory from 3 AM to 10 AM CST Monday for Pepin- Pierce. Winter Storm Warning from 3 AM to 6 PM CST Monday for Barron- Chippewa-Polk-Rusk. Winter Storm Warning from 3 AM to 10 AM CST Monday for Dunn-Eau Claire-St. Croix. && $$ UPDATE...MPG DISCUSSION...Borghoff AVIATION...MPG
Area Forecast Discussion
National Weather Service Morristown TN
951 PM EST Sun Feb 26 2023 ...New UPDATE... .UPDATE... Issued at 942 PM EST Sun Feb 26 2023 Forecast is progressing as expected. A strong shortwave across the Great Plains will quickly move northeast toward the Ohio Valley and Great Lakes by Monday afternoon. A 140 kt upper jet across the Great Lakes through the Mid-Atlantic will create an environment favorable to intensification of a surface low across the Ohio Valley. Strong gradient winds and a strong pressure gradient across the mountains will result in windy conditions area-wide, even for the valley, with mountain wave high winds across the mountains and western foothills. Have updated and continued the Wind Advisories and High Wind Warning. JB && .SHORT TERM... (This evening through Monday Night) Issued at 239 PM EST Sun Feb 26 2023 Key Messages: 1. Windy and warm conditions Monday along with numerous to widespread showers and a slight chance of some isolated thunder. Discussion: A stationary boundary remains in place to our south and the associated weak moisture convergence and saturated vertical profile has lead to persistent low clouds blanketing the region. Some light showers have been observed along and south of the I-40 corridor throughout the late morning and afternoon, with a few surface observations reporting some light drizzle as well. Lack of any large scale forcing has kept any QPF amounts little to none. Nonetheless, the majority of radar returns have dissipated at this point and most areas will remain dry until the increase of showers ahead of a cold front tomorrow, though spotty light rain/drizzle cannot be totally ruled out late this evening and early Monday morning. The main impact with Monday`s weather system remains the wind. A strong pressure gradient will develop as surface low pressure tracks from the Mississippi River Valley to the Great Lakes region, in addition to the development of an anomalous LLJ. Mixing heights upwards of 3500-4000ft and the strong pressure gradient will result in widespread southwesterly wind gusts of 40-50 mph by late morning and towards the evening hours. The 12Z HRRR and NAM3km both suggest that pockets of southwesterly flow at 850mb cloud amplify to as much as 60-70kts. While direction seems unfavorable for any downslope or mountain wave enhancement as the strongest flow settles in, I would not be shocked to see higher elevations reach high wind criteria. As such, have upgrade the previous wind advisory to a high wind warning in the GSMNP portion of the East Tennessee mountains. Gusts upwards of 65 mph will be possible. Outside of wind impacts, showers will become numerous to widespread by mid-day. Models have continued to trend with shifting the better forcing a little further north, minimal instability, and lackluster mid-level lapse rates. As such, SPCs marginal risk has been shifted further north. A few isolated rumbles of thunder remain a possibility. Temperatures will be well above normal under the strong southwesterly flow. && .LONG TERM... (Tuesday through next Sunday) Issued at 239 PM EST Sun Feb 26 2023 Key Message: Repeated rounds rainfall will potentially affect the area Wednesday night through Friday, with a possible threat of strong/severe storms Thursday into Friday. Discussion: A break from the rain and wind is expected on Tuesday with mostly clear skies and warm temperatures across the area as surface high pressure combines with a quick building mid-level ridge. These quiet conditions will likely only last for Tuesday and Wednesday before return to a rainy and stormy pattern for the second half of the work week. A frontal boundary will move into the area and should stall out in the vicinity of the Tennessee Valley. This boundary will become a focus for continued rainfall, moderate to heavy at times, from Wednesday night through Friday when it gets forced out from a strong low kicking out through the Ohio Valley on Friday. With quasi- stationary boundaries like this one, the forecast models can dramatically change QPF bulls-eye`s as time goes on, so there is not very high confidence in exact rainfall amounts at this time. But confidence is increasing that there will be rounds of moderate to heavy rainfall between Wednesday night into Friday. At this time expect widespread rainfall totals of over 2 inches between Wednesday and Friday, with isolated higher amounts due to the isolated/scattered nature of these showers. Some locations could see over 4 inches of rain for the second half of the week. So flooding will be the main weather concern, especially on Thursday night into Friday after rainfall from the previous days. In addition to the heavy rainfall and flooding potential, the strong low kicking out through the Ohio Valley thursday into Friday will bring with it a chance for strong to severe thunderstorms in the eastern Tennessee Valley. Still some large discrepancies on the exact location of the low and the most unstable atmosphere ahead of it, but will keep monitoring the trends for the potential of severe storms. Once the system finally moves through we`ll move into a drier and cooler pattern over the weekend with temperatures coming back down to seasonal normals. && .AVIATION... (00Z TAFS) Issued at 618 PM EST Sun Feb 26 2023 Poor flight conditions continue tonight into Monday as low clouds and areas of drizzle will persist near TYS and TRI tonight with MVFR and locally IFR cigs. Cigs lower at CHA later tonight with IFR conditions as S/SE flow and increasing moisture result in upslope conditions. SSW winds increase on Monday with gusts near 40 kt possible at all sites during the afternoon hours. These very strong near-surface winds will present a hazard to aviation on Monday afternoon. As convective showers move east across the region, locally stronger gusts will be possible. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 56 73 50 73 / 0 70 10 0 Knoxville McGhee Tyson Airport, TN 53 72 49 68 / 10 80 10 0 Oak Ridge, TN 53 70 47 69 / 10 90 10 0 Tri Cities Airport, TN 50 70 47 65 / 20 80 20 0 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...Wind Advisory from 10 AM to 7 PM EST Monday for Cherokee-Clay. TN...Wind Advisory from 10 AM EST /9 AM CST/ to 7 PM EST /6 PM CST/ Monday for Anderson-Bledsoe-Bradley-Campbell-Claiborne-East Polk-Grainger-Hamblen-Hamilton-Hancock-Hawkins-Jefferson- Johnson-Knox-Loudon-Marion-McMinn-Meigs-Morgan-North Sevier- Northwest Blount-Northwest Carter-Northwest Cocke-Northwest Greene-Northwest Monroe-Rhea-Roane-Scott TN-Sequatchie- Southeast Carter-Southeast Greene-Southeast Monroe-Sullivan- Unicoi-Union-Washington TN-West Polk. High Wind Warning from 10 AM to 7 PM EST Monday for Blount Smoky Mountains-Cocke Smoky Mountains-Sevier Smoky Mountains. VA...Wind Advisory from 10 AM to 7 PM EST Monday for Lee-Russell- Scott VA-Washington VA-Wise. && $$ SHORT TERM...KRS LONG TERM....ABM AVIATION...JB
Area Forecast Discussion
National Weather Service Pueblo CO
701 PM MST Sun Feb 26 2023 .UPDATE... Issued at 655 PM MST Sun Feb 26 2023 Have let Winter Weather Advisories come down for the southwest mountains and watching another increase in winds occuring along the eastern slopes of the southeast mountains, though so far they have not been as high as earlier NBM had suggested. High res models such as HRRR and early time steps of the 00z NAMNest suggest potential for high winds will continue through 1 AM in the gap flow areas along the southern I-25 corridor region. Will let High Wind Warnings continue with Pueblo and Eastern Fremont county expected to come down around 9 PM. -KT UPDATE Issued at 505 PM MST Sun Feb 26 2023 Based on latest high res model data and current forecast have extended the High Wind Warning for the southern Sangre De Cristo mountains until 08z in line with other high wind warnings along the southern I-25 corridor. The stronger gusts will stay confined to the lower eastern slopes where gusts up to 85 mph will be possible as the storm system rapidly intensifies across western KS. Have allowed all other scheduled High Wind Warnings to expire along the lower Arkansas River Valley, San Luis Valley and for the northern Sangres, Wets and Wet mountain Valley. Will need to watch the Pikes Peak region closely for a brief window of high wind gusts across the lower eastern slopes and western side of El Paso county this evening. Cross-sections do not look particularly favorable for mountain wave development and think the limited coverage should preclude the need for a High Wind Warning, but will be watching trends in observations and mesonet stations closely in case these conditions change. && .SHORT TERM...(This evening through Monday) Issued at 252 PM MST Sun Feb 26 2023 Key messages: 1) Strong winds the main concern the remainder of this afternoon into this evening. 2) Isolated thunder should push east by late this afternoon. 3) RED FLAG conditions over parts of the region tomorrow with gusty winds continuing. Impressive trough is moving over the region as I write. 3h P change chart is impressive, showing 10-11 mb pressure drops and 5-6 mb pressure rises behind the low. This indicates the surface cyclone is rapidly intensifying. Radar shows bands of showers and snow showers stretching SW-NE over the region, with some TSRA south of Baca county moving into SW KS as of 2 pm. KSPD has been gusting to 55 knts for awhile now. Rest of today into tonight... I believe any convection should be out of the region by mid to late afternoon. This convection will already enhance the strong winds which are already over the region. The main concern is going to be as the sfc system pushes east, the Isalobaric component (rapid sfc pressure drop) of the wind is going to allow strong winds to accelerate out of the mountains, and we will continue to have a high wind threat linger over the east slopes of the mtns, especially winds coming off Pikes Peak the wet mtns. For this reason I have extended the warning for Pueblo county into the evening hours and have added E Fremont into the warning. These strong winds will then continue over the s tier of the plains into late evening. With the winds keeping up tonight, plains will remain relatively warmer with low son the U20s to l30s. Valleys will radiate out as winds will quickly decrease and expect lows in the single digits mts/valleys. Tomorrow... Main concern if RED FLAG conditions. Gap flow winds are expected tot be rather strong tomorrow and RH values will crash. For this reason have issued a RED FLAG warning for the I-25 corridor from Pueblo down to the border, and this warning extends eastward out to the KLHX region. I would not be too surprised if this warning may need to be expanded by later shifts. Although it will be windy tomorrow, it will be relatively mild with 60s most of the plains with 50s El Paso. 40s in the SLV with teens and 20s mtns. .LONG TERM...(Monday night through Sunday) Issued at 252 PM MST Sun Feb 26 2023 Good model agreement continues through the extended period with better handling of the mid week storm. Ahead of this system, winds and fire weather will be the primary concerns. Monday night through Tuesday night...zonal westerly flow aloft will lead to continuous light to moderate snowfall along the Continental Divide. Several inches of new snow are expected, especially for areas over the San Juan range and Central Mountains. The main concerns will be across the Plains. Enhanced mixing of strong westerly flow aloft will lead to very windy conditions across the Eastern Mountains, into the Plains. The strongest winds are expected mainly along the lee slopes, east into the I-25 corridor. Gusts in excess of 55 mph are likely. Areas of blowing dust are likely, and will produce areas of low visibility on areas highways. Strong cross winds on north-south highways will also cause dangerous travel conditions. In addition to the strong winds, humidity values are expected to fall to near 15 percent. This will give us critical fire weather conditions for portions of the Plains. As far as highlights go, coordinated to Dodge City, Amarillo and Albuquerque to hold off given the current busy weather. High wind and fire weather highlights will likely be issued either this evening as the busy weather settles, or overnight on the mid shift. Wednesday and Thursday...the next upper storm system is forecast to track out of the Great Basin, across the Desert Southwest and into the southern Texas Panhandle. Expect snow to increase Wednesday across the Continental Divide, and persist through much of Thursday. Snow could be heavy at times, especially for the San Juan Range where southwesterly orographic flow is favored. Current projections of 10 to 15 inches are possible over the San Juans, with lesser amounts over the La Garita and Central Mountains. Across the Plains, model guidance is developing a surface low near Trinidad, and tracking it southeast. This will produce easterly wrap around flow across the Plains late Wednesday night into Thursday morning. Enhanced upslope flow into the southern I-25 corridor, east along the New Mexico border. A period of 6 to 12 hours of moderate snowfall may be possible over this area, with several inches of snow possible. For areas along Highway 50 and north, lighter snowfall is expected given the more southern track of the surface low, and northerly downslope winds off the Palmer Divide. Generally an inch or less of snow is likely. A few notes about this storm system and precipitation chances on the Plains. A slight shift in storm track and mean the difference of how much and where snow falls. Speed will also play a factor, and the current projections are pretty fast, which would limit snow amounts. A slow down would possibly mean more snow. Stay tuned! Friday through Sunday...another weak system in northwest flow will track across Colorado on Friday night with a quick burst of snow possible from the Palmer Divide, southeast across the Plains. Beyond this system, flat ridging will give way to southwest flow with periods of light snow possible along the Continental Divide through the weekend. Mozley && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 252 PM MST Sun Feb 26 2023 Strong gusty winds will continue rest of the afternoon into early evening, then let up somewhat tonight. Winds will once against become strong from the west tomorrow by late morning over all the the 3 taf sites, KPUB, KALS and KCOS. && .PUB WATCHES/WARNINGS/ADVISORIES... High Wind Warning until 1 AM MST Monday for COZ074-087-088-094- 099. High Wind Warning until 9 PM MST this evening for COZ083-086. Red Flag Warning from noon to 5 PM MST Monday for COZ228>232. && $$ UPDATE...KT SHORT TERM...HODANISH LONG TERM...MOZLEY AVIATION...HODANISH
Area Forecast Discussion
National Weather Service Tulsa OK
609 PM CST Sun Feb 26 2023 ...New SHORT TERM... .SHORT TERM... (Through tonight ) Issued at 608 PM CST Sun Feb 26 2023 Made a quick update to add a Dense Fog Advisory for far SE OK over the next several hours. Fog has become more widespread across eastern OK this evening in the saturated cool air on the north side of a sharp warm front down near the Red River. Guidance indicates that far SE OK will see more widespread dense fog for several more hours and thus an advisory was issued. The fog elsewhere should be more transient. The forecast for later tonight was left unchanged. A line of severe storms is expected to sweep across the region after 9 PM (trended a tad later than earlier progs). Some significant severe weather is possible, especially across northeast Oklahoma, with the latest runs of the HRRR simulating pockets of near 80 mph wind gusts punching into NE OK. At least marginally severe winds are possible with the squall line over into northwest Arkansas as well shortly after midnight. There`s also some indication that gradient winds from the west will pick up within an hour or two after the squall line and could reach advisory intensity. Going wind advisory for the region overnight should cover. Lacy && .LONG TERM... (Tomorrow through Sunday) Issued at 223 PM CST Sun Feb 26 2023 Gusty winds continue Monday with clearing skies and downslope wind component pushing high temps above the bias correct blended guidance. A similar warm pattern is in place Tuesday ahead of the next cold front passing Tuesday night. A chance of rain will spread across far southern locations Wednesday into Wednesday night with this frontal boundary. The next storm system has trended stronger in the latest deterministic guidance and there is now stronger agreement in the pattern. If this continues the precip chances for Thursday into Friday will trend upward area wide. Cold air will be lacking with this system however some snow potential may develop on the backside of this system and beneath the cold mid level temps. These details have time to be determined but the forecast will trend in this direction. && .AVIATION... (00Z TAFS) Issued at 515 PM CST Sun Feb 26 2023 IFR to MVFR conditions prevail this evening in advance of the severe line of storms expected to impact the areas sites later this evening and overnight. VFR conditions return late tonight into Monday. However, gusty west winds will winds will continue. && .PRELIMINARY POINT TEMPS/POPS... TUL 62 48 75 41 / 30 100 0 0 FSM 62 47 73 44 / 30 90 0 0 MLC 66 46 74 42 / 30 80 0 0 BVO 61 46 74 35 / 30 100 0 0 FYV 61 49 71 42 / 30 100 0 0 BYV 61 49 71 42 / 40 90 0 0 MKO 62 47 72 42 / 30 80 0 0 MIO 59 49 72 40 / 40 90 0 0 F10 63 48 73 42 / 30 90 0 0 HHW 68 49 73 42 / 20 80 0 0 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...Wind Advisory until 6 AM CST Monday for OKZ049-053>076. Dense Fog Advisory until 9 PM CST this evening for OKZ049-053. AR...Wind Advisory until 6 AM CST Monday for ARZ001-002-010-011-019- 020-029. && $$ SHORT TERM...30 LONG TERM....07 AVIATION...10