Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/22/23

Area Forecast Discussion
National Weather Service Boston/Norton MA
706 PM EST Tue Feb 21 2023 .SYNOPSIS... Another weak low tracks across northern New England this evening, bringing a brief period of light rain and snow to the area. Weak high pressure delivers mainly dry, seasonably cool weather Wednesday. A warm front likely brings a wintry mix of precipitation Wednesday night into Thursday night. Then bitter cold arrives later Friday into early Saturday. Snow showers possible Sunday. More wet weather possible early next week && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... Overall forecast remained on track this evening. Did tweak the precipitation timing based on the latest runs of the NationalBlend and time-lagged HRRR ensemble. Expecting precipitation to end from west to east between now and 1 AM. Still thinking only minor accumulations of either rain or snow. Brought temperatures back in line with observed trends. Previous Discussion... After a brief respite from the wet weather we continue our relatively active week of weather with a quick hitting light snow/rain event this evening into the early overnight hours. As this morning`s low pressure center moves further offshore another low begins to move from the eastern Great Lakes into southern Quebec while at the mid levels a weak shortwave disturbance lifts from eastern New York through New England. This, together with the low`s passing cold front will provide the necessary forcing for ascent to squeeze out some meager rain and snowfall. While some of the more recent high resolution guidance indicates the chance for widely scattered showers this afternoon the more appreciable showers arrive ahead of the cold front which should be knocking on the door of western MA and CT between 7 and 9 PM, reaching eastern MA around midnight. The showers themselves will lead the front, entering western MA closer to 3 to 5 PM and eastern MA by 6 to 8 PM. Precip exits west to east and will be out of southern New England by midnight. Given surface temperatures above freezing for much of the region this will be another elevation based snow event with the best chance of light snow in the Berkshires and Worcester Hills; even so, with the meager moisture available ahead of the front (PWATs <0.45") giving a few hundredths to a few tenth of an inch of liquid precipitation, and with the bulk of the precip moving through during the afternoon/evening hours (more marginal temperatures) snowfall accumulations are expected to be minor, generally up to 1 to 2 inches. The METRo Roadcast projects road temperatures in northern MA not falling below freezing until closer to midnight, after the precip has ended, so we expect any accumulation to be mainly on grassy surfaces rather than roads. The best shot of seeing 3+ inches on the grass will be for the typical jackpot areas in the northern slopes of the Berkshires but it is a low probability. By midnight the cold front has ushered in much colder and drier air, bringing precip to an end and low temperatures down into the 20s-low 30s. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY/... Our active and progressive weather pattern continues during this period as we see a ridge of high pressure briefly bring a quiet and dry period of weather for Wednesday before another winter weather system arrives Wednesday night. This storm starts as a low pressure over the Midwest Wednesday afternoon before it moves into NY/PA Wednesday night, generating a secondary low along the frontal boundary off the mid Atlantic coast overnight into Thursday. Precipitation arrives in western MA and CT after sunset Wednesday associated with the warm front extending from the parent low. Given this timing we`re not expecting an impact to the Wednesday evening commute. Temperatures through the column may be initially cold enough for this to start off as snow for some, though there remains much uncertainty as to the timing/details of this dynamic mixed precipitation event. There is high confidence in a stout warm nose around 800 mb which will produce sleet and freezing rain, eventually changing to rain. The low confidence comes with how quickly that warm nose moves in. The faster guidance would allow very little time for any snow, while the slower global guidance keeps precipitation as snow for several hours before flipping over. We are just getting into the window of the higher resolution guidance, and for now we`ll stick with a blend of the two solutions, with some minimal snowfall accumulations at the onset, northwest of the I-95 corridor, then flipping to sleet and freezing rain. Best shot at a few inches of snow will be for northern MA. Of greater concern for travel interests during Thursday morning`s commute will be the icy precipitation (sleet/freezing rain). For areas south and east of I- 95 a mostly rain solution is favored. Eventually the dry slot moves overhead Thursday morning bringing an end to precipitation by afternoon. After widespread highs in the 40s on Wednesday we`ll be cooler for most on Thursday. Given the path of the low, it will direct cold north/northeasterly flow into southern New England as it passes on Thursday so the warmest part of the day will be early, with colder air funneling in during the afternoon. Highs will be coldest in northern MA and warmest along the south coast. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... Highlights... * A wintry mix expected to end Thursday night, yielding slippery travel, especially across northern MA * Brief cold blast Friday afternoon into Saturday morning, with wind chills below zero Friday night * Becoming more likely that a low pressure remains too far offshore to provide much of an impact this weekend. * Another low pressure may provide a round of rain and/or snow early next week Active mid level synoptic pattern should become more zonal late this week, with a preferred storm track to our south and offshore. The amplitude of any longwave troughs or ridges is minimal, at least into this weekend. The pattern looks to become more amplified into early next week. Do not have a lot of confidence in the details, as the spread amongst the guidance members is fairly large. We have some time to iron out those wrinkles since it is a Day 6-7 forecast. At the surface, a low pressure moves away from our region Thursday night into Friday, bringing an end to our wintry mix. This is followed by a large high pressure moving from central Canada. This will mean a significant cooldown, especially Friday afternoon into Saturday morning. While not as cold as our brief arctic outbreak in early February, it will be noticeably colder than we have been. This high pressure should make it more likely for a low pressure to remain farther offshore this weekend. As mentioned above, still watching the track of a low pressure early next week. The exact timing will play a significant role in determining the amount of colder air still present across southern New England, which in turn will determine how much snow or ice we could see. At this moment, thinking more of a snow-to-rain scenario Monday into Tuesday. The NationalBlend modeled this well. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Tonight...Moderate confidence. Quick-hitting -SHRASN, ending from west to east between 02-06Z. Minor accumulations of SN possible at ORH. Expecting -RA elsewhere, but can`t rule out some brief -SN at other western MA/CT terminals. S/SE winds generally less than 15 kt. IFR/MVFR improving to VFR as precipitation comes to an end by 08Z. Stronger NW winds develop behind a passing cold front with isolated gusts 20-30 kt possible, mainly for south coastal terminals. Wednesday...High confidence. VFR, trending to low end VFR by late afternoon. NW wind becoming SW 10 kt. Wednesday night...Low confidence. VFR becoming IFR/LIFR by 06Z with arrival of mixed precipitation. Confidence on precip type is low but for interior terminals a SN to IP/FZRA to RA transition is likely between 0Z and 12Z. Light winds out of the south become easterly. KBOS Terminal...Moderate confidence in TAF. KBDL Terminal...High confidence in TAF. Expecting precipitation tonight to fall as RA given warm surface temperatures. Outlook /Thursday Night through Sunday/... Thursday Night: MVFR/IFR conditions possible. Strong winds with areas of gusts up to 45 kt. Chance RA, chance FZRA. Friday: VFR. Strong winds with gusts up to 50 kt. Slight chance FZRA. Friday Night: VFR. Windy with gusts up to 35 kt. Saturday: VFR. Breezy. Slight chance SN. Saturday Night: VFR. Chance SN. Sunday: Mainly VFR, with local MVFR possible. Breezy. Chance SN, chance RA. && .MARINE... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Tonight: High confidence. E/ESE winds shift to the W/NW behind a passing cold front. Gusty, with winds between 20-30kt possible. SCA goes into effect 00z this evening. Wednesday: High confidence. Dry. WNW wind becomes SW late as winds diminish, SCA continues for waves greater than 5 ft. Wednesday night...High confidence. Winds becoming SE and increasing to 15 to 20 kts gusting 20 to 25 kts by sunrise. Seas increasing to 2 to 4 ft. Outlook /Thursday Night through Sunday/... Thursday Night: Low risk for Small Craft Advisory winds with gusts up to 30 kt. Rough seas up to 7 ft. Chance of rain, chance of freezing rain. Friday: Moderate risk for gale force winds with gusts up to 45 kt. Rough seas up to 9 ft. Chance of snow. Friday Night: Low risk for gale force winds with gusts up to 35 kt. Areas of rough seas. Saturday: Winds less than 25 kt. Local rough seas. Slight chance of snow. Saturday Night: Winds less than 25 kt. Seas locally approaching 5 ft. Chance of snow. Sunday: Winds less than 25 kt. Seas locally approaching 5 ft. Chance of rain, chance of snow. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory from 11 PM this evening to 7 AM EST Wednesday for ANZ231>235-237-251. Small Craft Advisory until 1 PM EST Wednesday for ANZ250- 254>256. && $$ SYNOPSIS...Belk/BW NEAR TERM...Belk/BW SHORT TERM...BW LONG TERM...Belk AVIATION...Belk/BW MARINE...Belk/BW
Area Forecast Discussion...UPDATED
National Weather Service Corpus Christi TX
934 PM CST Tue Feb 21 2023 ...New UPDATE... .UPDATE... Issued at 915 PM CST Tue Feb 21 2023 Winds across the southern Coastal Bend have decreased below advisory levels, but remain strong. Have let the Wind Advisory expire at 9 PM as winds should generally remain at 20 to 25 mph with occasional gusts to 35 mph overnight. VAD Wind Profile indicated 35 knot winds around 2kft and models prog a LLJ to increase to 45-50 knots by 06Z. The RAP and HRRR show wind gusts around 45kt across interior portions of S TX overnight. However, models also indicate sustained winds of only 20-25kts. Am not so sure a 45kt LLJ will fully mix to the surface with lapse rates less than 4C/km. Gusts of 30-35mph look more likely to occur. && .SHORT TERM... (Tonight through Wednesday night) Issued at 355 PM CST Tue Feb 21 2023 As has been the case the last several days, temperatures and wind speeds have outperformed guidance. Southerly winds have increased to advisory levels over the southern Coastal Bend. A Wind Advisory is in effect until 9 PM this evening. NBM shows wind gusts may be near advisory levels over portions of the Brush Country later tonight. Windy conditions will occur across all of south Texas as the low level jet increases to 45-50 knots this evening and shift eastward toward the coast by daybreak. Sea fog persisted much longer than expected today. Expect wind speeds will inhibit dense fog formation tonight, but with warm moist air (dewpoints in the upper 60s) moving across cool water temperatures could lead to fog formation again later tonight. Surface trough/dryline is still on track to move through south Texas Wednesday as the upper level short wave trough moves to the northeast. With dry air mass and westerly surface winds, could see temperatures soar to near record levels. Went slightly above NBM guidance for highs. Record at LRD looks to be in jeopardy and CRP will be close. Afternoon RH levels will fall to 15 percent Brush Country to 25 percent inland Coastal Bend. But the wind speeds fall off by the afternoon, so only expecting near elevated fire danger conditions over the Brush Country in the afternoon. Onshore flow will bring boundary layer moisture back into the region Wednesday night. With warm air moving across the cool shelf waters, expect advection fog to occur along the coast and move inland into the coastal plains after midnight. && .LONG TERM... (Thursday through next Monday) Issued at 355 PM CST Tue Feb 21 2023 The GFS/NAM/ECMWF generally agree that an upper level disturbance will lift northeastward across the northern Plains/Great Lakes Thursday, while an upper ridge builds over the Gulf of Mexico. The upper pattern is predicted to become quasi-zonal Friday, except for the western CONUS as an upper disturbance approaches the West Coast. The GFS/ECMWF are generally consistent with the position/timing of this system, moving it across the southwestern CONUS/TX Sunday night/Monday. The foregoing upper pattern is expected to support onshore flow Thursday through Sunday, with PWAT values near/above normal. Based on the GFS soundings at select locations, radiation fog may occur early Thursday morning over the coastal plains, along with advection fog over the bays/nearshore waters when considering the predicted surface dew point temperatures related to current SST values. (Caveat, advection may be limited owing to weak flow). Deeper moist layer may preclude radiation fog early Friday morning. In response to an earlier upper disturbance expect to move across the U.S./Canada border in the Short Term, a frontal boundary is predicted to enter TX and stall just north of the CWA Friday, then lift northward Saturday. Unsure whether precipitation will occur Friday over the northern CWA. Convection not expected Saturday/ Sunday owing near zero CAPE/significant CIN, and no significant forcing. In response to the second upper disturbance, a frontal boundary/dry line is predicted to move across the CWA Monday. Given the expected lack of significant CAPE, and significant CIN in advance of the boundary, unsure whether convection will occur along the boundary. Decided to increase maximum temperatures Monday, as NWP models may not account for greater adiabatic compressional heating. && .AVIATION... (00Z TAFS) Issued at 531 PM CST Tue Feb 21 2023 Main concern tonight will be winds and low level wind shear. A 50kt low level jet is expected to develop this evening initially across the Brush Country then shifting east toward the coast through early Wednesday morning. Some of this energy will continue to mix to the surface, maintaining strong southerly winds with gusts around 35kt, especially for CRP TAF site, through the overnight hours. A boundary will move into the Brush Country between 11Z-13Z, and reaching the coast between 15Z-18Z. As the boundary moves east across S TX, winds will relax and shift to the southwest then west. The boundary is expected to stall close to the coast, then retreat westward as the sea breeze kicks in. This will shift winds back to the south across CRP by late afternoon and eventually all of S TX Wed evening. Winds will be much lighter Wednesday night. VFR conditions are expected through this evening, then MVFR conditions are expected across ALI, CRP and VCT by late evening then improving to VFR as the boundary brings drier air to the area. && .MARINE... Issued at 355 PM CST Tue Feb 21 2023 Moderate to strong onshore flow will increase to strong to very strong after midnight and continue through Wednesday morning. Some gusts to near gale force will be possible mainly over the offshore waters but could occur over the southern bays into this evening. Winds will decrease to moderate Wednesday afternoon but seas will remain elevated over the offshore waters into Wednesday evening. Patchy to areas of fog will be possible over the bays and near shore waters tonight and again Wednesday night. Advection fog may occur over the bays/nearshore coastal waters Thursday morning, however onshore flow may be too weak for advection fog. Greater onshore flow and expectation that surface dew points will exceed SST values suggest at least patchy advection fog Friday morning. Unsure whether surface dew point temperatures will exceed SST values and thus will not predict advection fog for Saturday morning. Persistent onshore flow and above normal moisture (based on the PWAT metric) predicted to occur Friday through Sunday. Moderate/strong south flow predicted for Sunday night, as an upper level disturbance approaches the region. A frontal boundary is expected to move offshore Monday. Unsure whether the boundary will trigger convection, and also unsure whether strong offshore flow will occur after boundary passage (colder air will not follow this boundary). && .PRELIMINARY POINT TEMPS/POPS... Corpus Christi 68 90 66 84 / 10 0 0 0 Victoria 67 87 65 82 / 0 0 0 0 Laredo 67 97 64 91 / 0 0 0 0 Alice 67 94 65 87 / 10 0 0 0 Rockport 67 83 66 76 / 0 0 0 0 Cotulla 64 95 60 89 / 0 0 0 0 Kingsville 68 94 66 87 / 10 0 0 0 Navy Corpus 67 84 67 75 / 10 10 0 0 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...None. GM...Small Craft Advisory until 10 AM CST Wednesday for GMZ231-232. Small Craft Advisory until 10 AM CST Wednesday for GMZ236-237. Small Craft Advisory until 6 PM CST Wednesday for GMZ250-255. Small Craft Advisory until 9 PM CST Wednesday for GMZ270-275. && $$ SHORT TERM...TE/81 LONG TERM....WC AVIATION...TE
Area Forecast Discussion
National Weather Service Cheyenne WY
708 PM MST Tue Feb 21 2023 .UPDATE... Issued at 704 PM MST Tue Feb 21 2023 Made a quick update to tonight`s forecast package with the arctic portion of the front coming in a little quicker, so updated temps and dewpoints with Chadron dropping from 36 degrees to 17 degrees in about 30 minutes earlier this evening. Current forecast through tonight looks on track and will continue to monitor trends in snowfall rates as well as wind speeds in the event that Blizzard Warnings need to be extended. && .SHORT TERM...(This evening through Thursday) Issued at 400 PM MST Tue Feb 21 2023 The anticipated major winter storm for portions of our area is beginning across portions of Southeast Wyoming and the Nebraska panhandle. While the forecast is largely on track, there have been a few minor but important changes with this update. The highlights are as follows: * A very high impact event is still on track for northern Carbon county, with snowfall accumulation in the 12 to 20 inch range and blizzard conditions expected to begin tonight. * A northward shift in recent model guidance has resulted in slightly reduced forecast snow totals for those along and south of a Laramie to Alliance line. Impactful snow is still expected, but totals have decreased slightly. * Dangerously cold wind chills are expected behind this arctic front. Apparent temperatures between -25 and -40F are likely for the majority of the forecast area Wednesday night into Thursday morning. A Wind Chill Watch has been issued. Currently, our area is under moist WSW flow aloft ahead of a potent trough rapidly digging into the west coast at this hour. The downstream branch of the trough is leading towards falling pressures over southwest Wyoming and northeast Utah as the lower atmospheric low pressure center starts to develop. Meanwhile at the surface, the arctic high is pushing southward. The combination of those two effects is rapidly reducing (and eventually reversing) the cross- barrier pressure gradient. Thus, the strong westerly winds have waned this afternoon after a very windy morning. Can`t rule out a quick burst of winds right before the front pushes through, but after that winds are expected to reverse. The cold front has already pushed into our northern counties, with Douglas reporting north winds, a temperature of 32, and light snow. Bitter cold temperatures are lagging behind the initial wind shift a little bit (still appears to be north of Rapid City at this time), but arctic air is still expected to reach the Colorado border by shortly after midnight. Snow has already begin in Carbon county per radar and webcams, but the blizzard conditions will likely hold off for a few more hours until the reverse gradients set up and initiate northeasterly winds. Further east, some light echos are showing up over the North Platte River Valley, with Scottsbluff reporting light rain for the last two hours or so. Some areas getting wet may see a flash freeze and icy conditions when the front passes through this evening and rain flips to snow quickly. Over the next 12 hours, the storm is expected to evolve rapidly. The upper level low will dig deep into the southwest this evening, and support low level cyclogenesis over central Utah. This progression has been the main source of the forecast uncertainty with this update. The 12z suite of hires models came in with a significant northward shift in precipitation, cutting down on totals for southern and eastern portions of the forecast area, while the global models still held strong with the higher end of the forecast. Digging into the details producing this difference, it could be seen that this change resulted from the positioning and strength of the low pressure center. The RAP model earlier was showing the 700-mb low positioned over SW Wyoming at 12z tomorrow, while the GFS was holding consistent with this feature over central Utah. The ECMWF and NAM were somewhere in between. This RAP solution then had a less amplified low, leading to southwesterly flow in the 600 to 800-mb level, rather than SSE flow. Such wind direction would be less effective isentropic lift and theta-e advection working into the I- 80 corridor near and east of Laramie. This presents a compelling failure mode that would result in the lower end of totals being realized in southern and eastern portions of the area (but would NOT affect totals in areas such as Rawlins, Wheatland, and Chadron). To account for these trends, amounts were trimmed slightly on the southern fringe. Did drop totals more significantly in Laramie, because a lack of dynamic lift aloft would result in much less snow, since orographics are very unfavorable there. Still looking at the low end of warning criteria for these zones, but a further northward shift could put that in jeopardy. However, 18z hires model trends have ended this northward shift, and even wobbled slightly further south, putting our official forecast that split the difference between the 12z global models and hires models in a good position. Further north and west, the forecast is still looking largely on track. Northern Carbon county from Elk Mountain to Rawlins still looks like it will see the most significant impacts. Model QPF means remain around 0.8 to 1.2, which supports the current forecast of 12- 20 inches of snow with locally higher amounts possible. Strong winds developing under impressive reverse pressure gradients are likely to produce gusty winds of 40 to 50 mph and blizzard conditions in this area. Significant blowing/drifting snow will compound the impacts. The heavy snowfall rates will be partially attributed to the strong frontogenesis predicted in this area, as the low-level front gets hung up on the mountains to the south. Models remain consistent in keeping this forcing over the area, which would lead to heavy banded snowfall. There is some variability in the exact location of the heavy band, which will likely be the difference between the lower and higher end totals described above. Heading over the the high plains north of the region of greater uncertainty described above, the isentropic lift and theta-e advection will be positioned well to still produce substantial lift and precipitation. Snow totals look on track here, but the piece of uncertainty going forward is the potential for blizzard conditions. There may be a period of winds reaching blizzard criteria along a band stretching across Niobrara county, northeast Goshen county, and just north of the North Platte River valley, and points northeastward. Don`t have the confidence at this time to upgrade to a blizzard warning due to uncertainty regarding now persistent these winds will be able to get, but will need to keep a close eye on wind and visibility trends as a potential upgrade could be needed. Regardless, winds will be enough to produce significant blowing/drifting snow through Wednesday morning, but we do thing winds should come down Wednesday afternoon. Another thing to watch for Wednesday is the potential for some convectively enhanced snow showers in the afternoon. Most guidance is showing steep lapse rates and some elevated instability on top of the bitter cold surface inversion. Thus, snow activity after midday Wednesday could take on more spotty, convective characteristics. Winds in the 600-800mb layer are expected to turn more westerly after 00z Wednesday, which will start to advect in drier air and bring an end to the snowfall totals. The forecast also remains on track for another significant cold air intrusion. Expecting almost the entire area except the higher terrain in the SW part of the forecast area to be below 10F by daybreak, and temperatures will only drop further through the day. Most will stay in the single digits above to single digits below during the daytime hours, with apparent temperatures between -20F and -25F even during the day. There is still strong model consensus for overnight lows in the -10 to -20F range Thursday morning. Even with just a little bit of wind, this would be enough to produce wind chills below -30F, so decided to issue a Wind Chill Watch for Wednesday night through Thursday morning. Weak warm air advection resumes Thursday, so the higher terrain should warm quickly (with breezy conditions likely leading to more blowing snow concerns), but the high plains will probably remain very chilly. .LONG TERM...(Thursday night through Tuesday) Issued at 400 PM MST Tue Feb 21 2023 The progressive large scale pattern will continue through the long term. The flow aloft splits Friday, with a southern stream upper low moving through CA/NV, the Four Corners and south central Plains this weekend into Monday. Shortwave energy in the northern stream dampens out, with a weak ridge shifting east ahead of the next Pacific upper trough Monday. This trough gets absorbed by a more dominant upper ridge, deamplifying Tuesday as a deeper upper trough takes shape over the western CONUS. Main concern for Friday through Saturday will be the resumption of strong winds for the I-25/I-80 wind-prone zones. The 12Z in-house random forest probabilities for high winds are around 40 percent, with gusts falling just short of 58 MPH. Another byproduct of the winds will be blowing/drifting of the newly fallen snow. Travel will be impacted with the possibility of ground blizzard conditions. Winds diminish Saturday night and Sunday, then strengthen Sunday night and Monday. Probabilities for high winds along the I-80 corridor from Rawlins to Buford are 60-65 percent with gusts up to 65 MPH. There will be some Pacific moisture interacting with a passing shortwave and orographic lift Friday to produce snow showers along and west of the Laramie Range. One to three inches of snow will be possible over the Snowies/Sierra Madres. Saturday will be dry, with the next chance of mountain snow showers Sunday/Sunday night and Tuesday with the passage of additional shortwaves. Temperatures moderate from the 20s/30s Friday to the 30s/40s Saturday and Sunday. Temperatures cool slightly Monday following a frontal passage, then moderate once again Tuesday. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 423 PM MST Tue Feb 21 2023 Wyoming TAFS...A strong cold front will move across the terminals around mid evening with winds becoming north and northeast and widespread snow developing by late evening with IFR ceilings and visibilities continuing through the period. Nebraska TAFS...A strong cold front will sweep across the terminals this evening with winds becoming northeast. Widespread snow will develop behind the cold front late this evening producing IFR ceilings and visibilities through the period. && .FIRE WEATHER... Issued at 227 AM MST Tue Feb 21 2023 Fire weather concerns will not be present for the next several days as a strong cold front and accumulating snowfall occurs across the region. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...Winter Storm Warning until 5 AM MST Thursday for WYZ101>103- 106>108-111>114. Wind Chill Watch from Wednesday afternoon through Thursday morning for WYZ101>110-115>119. Winter Storm Warning until 5 AM MST Thursday for WYZ116>119. Winter Weather Advisory from 11 PM this evening to 5 AM MST Thursday for WYZ115. Blizzard Warning until 5 AM MST Thursday for WYZ104-105-109-110. NE...Winter Storm Warning until 5 AM MST Thursday for NEZ002-003-095- 096. Wind Chill Watch from Wednesday afternoon through Thursday morning for NEZ002-003-019>021-054-055-095-096. Winter Storm Warning until 5 AM MST Thursday for NEZ019>021-054. Winter Weather Advisory from 11 PM this evening to 5 AM MST Thursday for NEZ055. && $$ UPDATE...TJT SHORT TERM...MN LONG TERM...MAJ AVIATION...RUBIN FIRE WEATHER...BW
Area Forecast Discussion
National Weather Service Des Moines IA
603 PM CST Tue Feb 21 2023 ...Updated for the 00z Aviation Discussion... .DISCUSSION.../Tonight through Tuesday/ Issued at 309 PM CST Tue Feb 21 2023 Key Messages: -Significant Winter Storm with heavy snow north to ice and sleet into central Iowa tomorrow into Thursday -Breezy northwest winds on Thursday Discussion: An elongated wave across the upper midwest has brought snow to Minnesota and skimmed across far northern Iowa this afternoon. While accumulations have remained fairly light, brief reductions in visibility to a mile or less have occurred. At the same time, temperatures have under performed today by several degrees as east southeast winds provide an unfavorable trajectory for much warming today. The large, much talked about, system of note will make its presence known beginning tomorrow morning. Deep moisture transport out of the south phases with the northerly elongated wave as the surface low bottoms out across the central plains. What does this mean for Iowa? Let`s take this in phases. Rain will initially move into southern Iowa early Wednesday morning and expand into central Iowa. As temperatures near freezing are encountered, a transition to freezing rain is expected, generally in the vicinity of the interstate 80 corridor. Further north towards the highway 30 to highway 20 corridor sleet is also anticipated. And finally, far northern Iowa will see mainly snow, with potentially heavy accumulations along the Iowa-Minnesota border. The primary cause of this precipitation type transition is a nose of warm air easily identified on a cross section across Iowa. as the depth of the surface cold layer deepens to the north and the warm layer cools, we see that transition from rain to freezing rain to sleet to all snow. There are a few variables which will influence just how much ice accumulates and where. High rain rates mean more chance for runoff and thus less ice accumulation. Keep in mind that a degree or two change in temperature, at the surface or aloft, could make an impactful difference in the forecast. A few convective elements are possible within this as well, with that additional lift within cells that would contribute to more sleet and less freezing rain. Across the models, the GFS tends to be slightly further south with the wintry mix of ice and sleet nearer the interstate 80 corridor compared to the Euro which is further north closer to the highway 30 corridor. In the hi-res world, the HRRR and RAP tend to agree with a similar northerly track with the wintry mix, while the HREF is more robust south of there. These are distances of 20 to 30 miles with potential significant impacts, as accumulations of a quarter inch or more of freezing rain is possible. Winds will remain breezy on Wednesday but increase further on Thursday as the system departs. Breezy winds across northern Iowa on Wednesday into Thursday will contribute to reduced visibility as times. Any winds in areas with ice accumulations could contribute to possibilities for tree damage and power outages. As winds increase across southern Iowa on Thursday, gusts nearing 40+ mph are possible and a wind advisory may be needed. Lastly, there is a chance that the narrow warm sector reaching into far southern Iowa could result in a few thunderstorms with elevated CAPE of 100-300 J/kg. The primary severe risk is south of the area into Missouri. Much colder air will filter in behind the system and temperatures will drop below zero across much of Iowa into Friday morning. With breezy winds, wind chill will be well below zero and the need for a wind chill headline cannot be ruled out across parts of northern to northwest Iowa. && .AVIATION.../For the 00Z TAFS through 00Z Wednesday evening/ Issued at 600 PM CST Tue Feb 21 2023 VFR conditions will prevail during the first portions of the TAF period, then quickly degrade into MVFR/IFR and even possible LIFR from ceilings and visibilities. Conditions will be driven by periods of SN/PL/FZRA/RA from north to south across the sites. Concurrent with the precipitation will be gusty NE winds, especially across northern sites KFOD/KMCW/KALO where gusts will be up in the 30s kts during the latter half of the period. && .DMX WATCHES/WARNINGS/ADVISORIES... Winter Storm Warning from 9 AM Wednesday to 6 PM CST Thursday for IAZ004>007-015>017-023>025. Ice Storm Warning from 9 AM Wednesday to 6 PM CST Thursday for IAZ026>028-037>039. Winter Weather Advisory from 9 AM Wednesday to 6 PM CST Thursday for IAZ033>036-044>050-057>062-070>072. && $$ DISCUSSION...Hagenhoff AVIATION...Curtis
Area Forecast Discussion
National Weather Service Grand Forks ND
939 PM CST Tue Feb 21 2023 .UPDATE... Issued at 939 PM CST Tue Feb 21 2023 Light snow band continue to sag further south, and the first round of precipitation should push out of our area sometime after midnight. Snow will begin to move back in by tomorrow afternoon for the second round. Across the northern counties, skies have already cleared out and wind chills are below -25 in many areas. However, expecting temps and wind chills to get even colder, and the wind chill warning and advisory headlines start very soon. Will leave headlines as they are for now. UPDATE Issued at 544 PM CST Tue Feb 21 2023 Decent snow coming down across our southern counties with 3 inches so far in Lidgerwood. Radar has the snow band starting to weaken a bit, but adjusted POPs for current trends. Overall forecast seems on track for the time being and no changes planned for headlines. && .SHORT TERM...(This afternoon through Tonight) Issued at 214 PM CST Tue Feb 21 2023 Key Messages: -Winter weather impacts remain likely through the afternoon/evening hours across southeastern North Dakota into west central Minnesota. -Cold, well below zero temperatures and gusty winds will lead to dangerously cold wind chills overnight into Wednesday morning. Discussion... As of this afternoon, a midlevel convergent zone was noted on latest RAP mesoanalysis. This correlates well with a region of 700 hPa frontogenesis, which is leading to an area of snowfall across southeastern North Dakota into west central Minnesota. The heaviest snowfall rates are tied to the frontogenesis region, which is generally located near the border of the Dakotas. Regardless, transient periods of moderate to heavy snow have been observed with these frontogenetical bands. Upstream visibility reductions down to 1/4 mile at times have been reported underneath the heaviest bands of snow. Additional snowfall amounts of 1 to 4 inches will be possible as this system moves through. Given the overall transient forcing for ascent, anticipating this to be a quick moving system, with snowfall chances decreasing rapidly as we move into the evening hours. As snowfall chances diminish tonight, skies are expected to clear over at least the northern half of the forecast area, leading to another cold night ahead. Especially where clearing works in, temperatures should be able to drop quickly back below zero. With increasing winds also expected overnight, wind chill values in the - 30s to -40s will be possible, with a few -50s not out of the question. .LONG TERM...(Wednesday Morning through Tuesday) Issued at 214 PM CST Tue Feb 21 2023 ...MAJOR WINTER IMPACTS TOMORROW AND THURSDAY... KEY MESSAGES 1. Blizzard conditions will develop from south to north during the day Wednesday up to the Highway 200 Corridor. 2. Heavy accumulating snow from southeast North Dakota through Wadena County of 6 to 10 inches, with areas approaching a foot. 3. Accumulating snowfall between 2 and 6 inches mainly south of Highway 200. 4. Dangerous wind chills approaching 50-below at times will occur through at least Thursday. 5. Travel will be life-threatening to those stranded, especially in southeastern North Dakota and west-central Minnesota where snowfall accumulations may exceed 8" with significant drifts and dangerous wind chills. DISCUSSION... The well-advertised winter storm is on our doorstep. Satellite analysis indicates our twin-headed lows spinning over the Baja of California and the Pacific Northwest respectively. As these continue to push eastward overnight tonight, a coupled jet is expected to develop over the midwest. This will allow for strong surface cyclogenesis tomorrow. With most guidance spitting out a minimum pressure approaching 990mb sandwiched with a 1040mb high over the Yukon and western Alberta, a gradient wind response will develop over the CWA. BUFKIT momentum transfers indicate the potential for winds to approach 25-30 knots assuming maximum momentum transfer. However, with limited cold air advection to punch down those max winds, the general thought here is that winds will be much less than the max momentum transfer (by between 5-8 knots). While current snowpack is VERY blowable, winds should be limited enough overnight that impacts will remain relatively isolated and minor. Blowing snow probabilities within this timeframe through 3 PM tomorrow are in the 10-20% range due to the limited winds. Conditions will deteriorate very quickly as snowfall arrives to the southern Red River Valley after noon tomorrow. Blowing snow probabilities with mostly stable winds between 20 and 25 knots combined with the falling snow spit out probabilities approaching 100, particularly after sunset Wednesday through Thursday morning. With the current blowability of snow, significant drifting will Not worth putting out an advisory headline for a few hours. develop across southeast North Dakota through west-central Minnesota into Wadena. Combine this with the long duration of the snowfall and the high predictability in warm air advection, there is high confidence in the snowfall ranges across the entire region. Higher totals exceeding 8 inches remain possible in southeastern North Dakota and west-central Minnesota (30-60% probability, increasing southward). Regardless of the snow totals that are experienced, the winds will be there for blizzard conditions within the blizzard warning. We know there will be falling snowfall combined with the elevated winds to create a prolonged period of blizzard conditions. Conditions will be especially significant in the tri-state area where significant snowfall accumulations approaching a foot with the winds will create the potential for significant drifting. For this reason, the expectation is for the worst conditions to be felt in southeastern ND and WC MN. Very difficult to impossible travel conditions will occur in these regions. Combine these with the dangerous wind chills approaching 35 and 45 below, travel will be life-threatening to those stranded. Further north, blizzard conditions will impact the area despite the limited accumulation potential. Falling snow and winds will create whiteout conditions up to the Highway 200 corridor. Areas of blowing snow may exist outside of these areas, however blowing snow impacts should remain limited due to limited wind speeds and lack of falling snow. Wind chill impacts of at least 30-below will impact most of the area at some point between tonight through Thursday afternoon. Conditions for travel should improve as winds diminish Thursday afternoon. Impacts look to remain limited to wind chills through the rest of the work week, with gradually warming temperatures towards the end of the period. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 544 PM CST Tue Feb 21 2023 Light snow impacting KFAR has brought vis down to 1-2SM at times, but ceilings there and conditions at all other sites are VFR. With dry air coming in from the north think that conditions will be mostly VFR for much of the period until winds increase and we start to get lower visibility from blowing snow tomorrow afternoon. Winds will stay mostly in the 350 to 020 range for most of the period, picking up in speed with gusts over 25 kts by Wednesday afternoon at least for the ND airports. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...Wind Chill Warning until noon CST Thursday for NDZ006>008- 014>016-024-026-027-054. Blizzard Warning from 6 PM Wednesday to noon CST Thursday for NDZ028>030-038-039. Winter Weather Advisory until 6 PM CST Wednesday for NDZ038-039. Winter Weather Advisory until 3 PM CST Wednesday for NDZ049-052- 053. Blizzard Warning from 3 PM Wednesday to noon CST Thursday for NDZ049-052-053. Wind Chill Warning until 6 PM CST Wednesday for NDZ028>030. MN...Wind Chill Warning until noon CST Thursday for MNZ001-004-007. Wind Chill Advisory until 6 PM CST Wednesday for MNZ002-022-023. Blizzard Warning from 6 PM Wednesday to noon CST Thursday for MNZ002-003. Winter Weather Advisory until 6 PM CST Wednesday for MNZ003. Wind Chill Advisory until noon CST Thursday for MNZ005-006-008- 009-013>017. Winter Weather Advisory from 6 PM Wednesday to noon CST Thursday for MNZ022>024. Winter Weather Advisory until noon CST Thursday for MNZ027-028. Winter Weather Advisory until 3 PM CST Wednesday for MNZ029>032- 040. Blizzard Warning from 3 PM Wednesday to noon CST Thursday for MNZ029-030-040. Winter Storm Warning from 3 PM Wednesday to noon CST Thursday for MNZ031-032. && $$ UPDATE...JR SHORT TERM...Rick LONG TERM...Perroux AVIATION...JR
Area Forecast Discussion
National Weather Service Green Bay WI
830 PM CST Tue Feb 21 2023 New Information added to update section .UPDATE... Issued at 829 PM CST Tue Feb 21 2023 The latest RAP analysis and satellite/radar imagery show a deformation zone extending across central Minnesota and northern Wisconsin this evening. 800-700mb frontogenesis south of this axis is helping to generate a swath of snow, which has been spreading east across western and central WI this evening, and reaching the Oshkosh area at around 8 pm. The snow has yet to reach north of HWY 29 and east of US 51, thanks to residual dry air below 800mb. However, mesoanalysis is showing low level saturation spreading east into north-central WI and think snow will start to reach the surface over the northwoods shortly. But with the slower start, trended downward with snowfall amounts across far northern WI. This may mean that the northern tier of counties within the winter weather advisory will struggle to reach 3". Otherwise, a snowfall axis of 3-5" south of HWY 29 is looking good so far this evening. No changes to the winter weather advisory for tonight. && .SHORT TERM...Tonight and Wednesday Issued at 243 PM CST Tue Feb 21 2023 Headline changes include an eastward expansion of tonight`s Winter Weather Advisory, an upgrade of the Winter Storm Watch to a Warning, with an earlier start time over our southern counties. Lake-induced low clouds lingered across northern WI, as mid/high clouds quickly approached from the west. The regional radar mosaic showed snow moving into eastern MN. Strong frontogenesis, 850/700 mb warm air advection and the RRQ of an upper level jet will overspread the forecast area during the late afternoon and evening, causing light to occasionally moderate snow to develop, then continue through the night. With a cold air mass and deep dendritic growth zone in place, expect a widespread powdery accumulation of 3 to 5 inches across roughly the southern 2/3rds of the forecast area. Have expanded the Winter Weather Advisory eastward into Oconto, southern Marinette and Door counties. The snow should diminish Wednesday morning, but models show a quicker return of significant snow accumulations into central and east central WI during the afternoon, as strong mid-level WAA/isentropic lift arrives. Northeast winds will increase during the day, and gust to 25 to 35 mph north, and 35 to 45 mph south in the afternoon. Considerable blowing or drifting snow is expected, especially in opens areas of central WI, the Fox Valley and lakeshore. The Watch has been upgraded to a Warning, and the start time has been tiered from noon in our southernmost counties to 6 pm in northern WI. .LONG TERM...Wednesday Night Through Tuesday Issued at 243 PM CST Tue Feb 21 2023 The main focus of the extended period will be the resolution of the winter storm passing over the area from the middle of the week through Thursday. Wednesday night through Thursday... The winter storm will be ongoing over the beginning of the extended period as the surface low lifts out of the Central Plains and into Iowa through the overnight. The associated warm front will lift towards the southern Wisconsin border during this period, bringing overrunning warm air and moisture well into Wisconsin. As a result, a fairly tight baroclinic zone will be over southern Wisconsin with strong FGEN forcing north of this area in central and northern Wisconsin. Upper level support will not be lacking during this period either, as a pair of upper jets rotate over the region. Snow fall rates will likely be high at times, with rates up to an inch an hour not unlikely through Thursday morning. Added to this, wind gusts will range from 30 to 45 mph at times, creating near whiteout conditions overnight. As the surface system departs northeastwards towards lower Michigan Canada Thursday morning, the most intense snowfall will lift into northern WI. By the early afternoon, overall intensity will be headed downwards, with gradually diminishing winds and snowfall. That said, snow will likely become more fluffier as the day wears and colder air wraps into the region. This could keep a prolonged period of lower visibility in place into Thursday afternoon as the newest snow remains more prone to blowing and drifting despite the slowly decreasing wind gusts. All is said and done, snowfall totals from Wednesday night through Thursday afternoon are expected to be between 5-10 inches south of a line from Wisconsin Rapids to Oconto, and 10-15 north of this line. Given the wind during this period, measuring will be fairly difficult as there will likely be marked difference between open areas and the tallest drifts. Thursday night and Friday... Any remaining light snow will move out of the region Thursday evening and overnight. A fairly cold and dry airmass will be in place through the surface for this period, creating a fairly cold night for the region. Friday morning wind chill values across portions of central to north-central will likely be in the 10 to 20 below zero range. That said, WAA will pick up again over the day Friday but moisture will likely be insufficient to produce any precipitation during the day. By the early evening and early overnight, models do produce sporadic chance pops across the area, but the overall impact will likely be low. Stuck to blended guidance for this period. Rest of the forecast...The weekend will see moderating temperatures, with highs gradually headed back into the 30s to lower 40s by Monday. The next active weather system could arrive early next week, but given the temperatures in the forecast, currently would expected primarily rain as the dominant p-type. && .AVIATION...for 00Z TAF Issuance Issued at 542 PM CST Tue Feb 21 2023 - A large area of snow will spread across the region from west to east through 9 pm. Widespread IFR visibilities and MVFR ceilings can be expected in the snow through late tonight. Local reductions of visibilities to LIFR are possible. Several inches of dry snow are likely. - The snow may diminish somewhat Wednesday morning, but will intensify from south to north during the afternoon as a winter storm approaches from the Southern Plains. - Northeast winds will be increasing through the day. Gusts of 30 to 40 mph are likely during the afternoon. The gusty winds combined with the new snow will lead to reduced visibilities in blowing snow. && .GRB WATCHES/WARNINGS/ADVISORIES... Winter Storm Warning from 6 PM Wednesday to 6 PM CST Thursday for WIZ005-010>013-018-019-021-073. Winter Weather Advisory until 9 AM CST Wednesday for WIZ018>022- 030-031-035>040-045-048>050-073-074. Winter Storm Warning from 3 PM Wednesday to 6 PM CST Thursday for WIZ020-022-030-031-035>040-074. Winter Storm Warning from noon Wednesday to 6 PM CST Thursday for WIZ045-048>050. && $$ UPDATE.........MPC SHORT TERM.....Kieckbusch LONG TERM......Uhlmann AVIATION.......MPC
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1028 PM EST Tue Feb 21 2023 .SYNOPSIS... A warm front will lift north of our area on Wednesday with temperatures continuing to warm. A strong upper level ridge will dominate our weather through Thursday with daily and perhaps even monthly record highs expected to be broken. Another cold front will pass Friday, with chilly and damp weather looking likely on Saturday. && .NEAR TERM /THROUGH WEDNESDAY/... As of 1030 PM EST Tuesday: Warm frontal activation is being depicted based on current dewpoint and wind observations and where very isolated showers have developed, with 50s in the southern half of the CFWA, while 30s still reside along the I-40 corridor. No major changes to the overall forecast as it remains on track. Updated temperatures and PoPs based on model trends and current observations. Otherwise, quasi-zonal flow will persist across much of the East through the near term, cyclogenesis is underway in the lee of the Rockies in response to height falls emanating from the western Conus. This will activate the broad baroclinic zone across the Southeast tonight into early Wed, with resultant weak warm front expected to lift across our CWA during that time frame. Some high resolution particular the HRRR develop scattered showers across the area beginning this evening, with some support from this from some traditional guidance sources. Overall, there is enough of a signal there to warrant 20-30 PoPs across much of the forecast area tonight. While statistical guidance signals are mixed, some fog...possibly locally dense could develop in the vicinity of the warm front, but this will at least partly depend upon how much...if any...precip falls. Min temps will remain well above climo...right around where highs should be for the time of year. Warm front is expected to lift north of the area by late Wed morning, bringing an end to shower chances. Some guidance, in particular the NAM tends to saturate the low level air mass in response to light precip...developing a bit of an situ cold air damming scenario over the I-40 corridor. This seems somewhat dubious, and the NAM appears to be overproducing precip to some extent, but it does create a bit of uncertainty re: Wed max temps, especially across northern zones. Nevertheless, the most likely outcome is another day of well-above normal max temps, with mid-to-upper 70s likely along and southeast of I-85, and lower 70s across the mtn valleys and I-40 corridor. && .SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/... As of 121 PM EST Tuesday: The short term portion of the forecast period will be dominated by an anomalously strong sub-tropical ridge centered over far southern Florida. Latest guidance continues to indicate a 597dam H5 height contour with anomalous heights in the 99th percentile for late February extending well into the Carolinas and northeast Georgia. A weakening shortwave trough lifting through the Ohio Valley will drag a weak boundary/convergence zone into the Appalachians tomorrow night into Thursday morning. Isolated to scattered showers are expected across the mountains, but upper forcing quickly lifting away and rising heights will keep this activity confined to the high terrain during the morning hours. The main focus will be temperatures on Thursday, which will flirt with all time February highs at many locations. Forecast confidence has decreased slightly as morning low stratus could delay warming. Cloud cover will eventually lift and scatter, but exactly how long that takes remains to be seen. Regardless, at least partly cloudy skies should be common by late morning to early afternoon which should still support afternoon highs climbing into the low 80s east of the mountains within a deeply mixed boundary layer. Mountain valleys will likely see highs top out in the mid to upper 70s with 60s across the highest terrain. Both morning low temperatures and afternoon highs will be running 20-25 degrees above average. Previously mentioned deep mixing will also support breezy conditions, but current forecast gusts are expected to remain below wind advisory criteria at this time. A better defined shortwave trough lifting through the Great Lakes region on Thursday will send a surface cold front through the area Thursday night into Friday morning. The arrival of a cooler and drier airmass will help knock temperatures down to where records won`t be in jeopardy, but temperatures will still be above normal. The frontal boundary will likely stall just to our south as it becomes oriented parallel to westerlies on the poleward side of the sub-tropical ridge. Spokes of DPVA embedded within the upper flow along with ascent from upper jet dynamics will help instigate precipitation along and north of the frontal boundary on Friday. && .LONG TERM /FRIDAY THROUGH TUESDAY/... As of 203 PM EST Tuesday: Rain will peak in coverage Friday night through Saturday as a subtle shortwave trough slides through the region. A transient surface high shifting across New England will support a hybrid/insitu CAD wedge as well with a damp/cool day in store for most, especially across the North Carolina counties. Temperatures will likely be several degrees below average, which will be quite a pattern change from the warmth on Thursday. Westerly downslope flow and drying will quickly clear out precipitation by Sunday morning with only a few showers lingering along the Tennessee border. This will allow for temperatures to quickly return to above average on Sunday with highs in the low 50s to 60s for the mountains and upper 60s to low 70s to the east. Heading into early next week, guidance is in good agreement on a compact negatively tilted trough ejecting out of the Desert Southwest on Sunday and lifting through the Lower Mississippi Valley and into Ohio on Monday. While guidance agrees on the presence of a wave, there are differences in regards to track and strength and any corresponding sensible weather impacts to the area. The GFS solution is the most aggressive with a potent wave and a strongly forced QLCS entering our western zones Monday evening, although quality of moisture return and subsequent instability looks meager at best. The ECMWF/CMC/ICON solutions have a weaker wave with the strongest height/pressure falls brushing by the area to the north and mainly a weak band of showers moving into the mountains. Kept the forecast in line with the national model blend for now until guidance comes into better agreement with the evolution of the wave. && .AVIATION /04Z WEDNESDAY THROUGH SUNDAY/... At KCLT and elsewhere: VFR w/ mainly SCT/BKN high clouds are expected to persist through at least this evening. Winds have diminished to 5 kts or less this evening before increasing to 10-15 kts during late morning/early afternoon Wed. Otherwise, low level moisture is expected to return from the SW overnight in association with a developing/weak cold front. This will bring shower chances... mainly to the upstate SC terminals and KCLT, warranting VCSH at those sites. Cig restrictions are also expected to develop toward sunrise Wed, with MVFR cigs becoming likely at most sites, and IFR well within the realm of possibility. Cigs should at least begin to improve by the end of this forecast cycle. Fog could pose a problem if the warm front sets up shop within the vicinity of the terminals around daybreak Wednesday, but confidence is too low for a mention in the latest TAF update, but will continue to monitor trends. Outlook: Weak frontal boundaries will linger in or near the region for much of the week, leading to occasional unsettled weather. Periodic restrictions are possible due to low clouds and/or precipitation at times during the latter half of the week. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None. && $$ SYNOPSIS...DEO NEAR TERM...CAC/JDL SHORT TERM...TW LONG TERM...TW AVIATION...CAC/JDL
National Weather Service Wilmington OH
1013 PM EST Tue Feb 21 2023 .SYNOPSIS... Showers and strong winds are forecast to develop tonight through Wednesday night as low pressure tracks to the Great Lakes. Strong winds are expected again on Thursday in the vicinity of a cold front trailing the Great Lakes low. Colder temperatures and dry weather follow the front for Friday. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... Evening update... A few minor adjustments to the forecast this evening most of which was in an attempt to sharpen up the forecast (PoP, wind gusts, temps/dewpoints) based on latest guidance increasing confidence. For PoPs this evening, increased to 80-90% as the elevated activity spreads northeast overnight. Elevated CAPE and strong flow likely yields some hail with the strongest activity. Can`t rule out a few special weather statements during the early morning hours. With more high- resolution guidance coming in, a much stronger temperature gradient (15-20 degrees within a few counties north to south) looks to exist along the frontal boundary tomorrow as it slowly moves northward. Also timed the strongest wind gusts for locations south of the front during the afternoon. Not expecting strong wind gusts to mix down elsewhere. The one component that did not make it into the forecast due to the uncertainty is the potential for fog along and ahead of the frontal boundary during the morning and early afternoon hours. HRRR guidance has been consistent with the signal for it occurring, but rather sporadic with timing and intensity. Final adjustment was to slow the advancement of strongest wind gusts and decrease overall wind potential north of the boundary. Still think the strongest winds will be dependent on the northward position of the front and how efficient clearing ultimately is. Wind gusts remain near wind advisory over the currently advised area so will make no changes to it. Afternoon discussion...(issued 330 PM) Persistently strong winds this afternoon will diminish for a few hours this evening as high pressure builds in briefly. Issued SPS to highlight gusts around 40 mph through 4 pm along and north of I-70. For tonight, the surface high will be east of the area by 10 pm, while a warm front containing a band of isentropic lift moves in ahead of low pressure. Showers are forecast to overspread the area from south to north following the movement of the warm front. Thunderstorms will also be possible from an environment containing ample elevated CAPE and potent winds aloft. Under those very strong wind fields aloft, gusty winds will mix to the surface south of the warm front, leading to some gusts over 20 knots by 6 am. This will cause low temperatures to be around midnight in the mid 30s north to mid 40s south, with readings rising toward daybreak in mixing and warm advection. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/... Warm front with showers will be moving to Northern Ohio on Wednesday, leaving the ILN area in the well mixed warm sector. Mainly dry and windy conditions are expected as a very strong low level jet is mixed closer to the ground. Have issued a wind advisory for the west half of the FA starting at 11 am, with expansion farther east possible depending on later guidance. Much above normal temperatures can be expected, with the high at CVG around the daily record of 71. Readings as high as the mid 70s are forecast for southeast counties, while northern locations may be limited to the 60s. For Wednesday night, another band of showers and possible thunderstorms is forecast to swing across the area from west to east, containing more strong wind gusts. Therefore, the wind advisory remains in effect until 1 am Thursday. Drier air and somewhat lower wind speeds arrive later Wednesday night in the rapidly progressing weather pattern. && .LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... On Thursday morning, an area of surface low pressure will be moving ENE into the southern Great Lakes. The Ohio Valley will be well in the warm sector of this system on Thursday, with strong theta-e advection on deep- layer southwesterly flow. Even with the warm advection pattern, there is decent model agreement on a well mixed boundary layer, and wind gusts of 35-45 MPH appear likely. Definitely a chance of getting into advisory criteria (46 MPH or greater) on Thursday, particularly in the northern half of the forecast area. Temperatures are another item of note for Thursday, with values forecast to be near records. The standing record high temperatures for Thursday (Feb 23) are as follows. Cincinnati 72 in 1996 and 1985 Dayton 70 in 2017 Columbus 72 in 2017 One thing not being mentioned for Thursday is precipitation, as it looks like any warm advection precipitation should be clearing the area by morning, and forcing appears to remain north of the area beyond then. A cold front Thursday afternoon and evening will be running into very dry air, and is unlikely to produce any precipitation. Behind the cold front, Friday looks like the coolest day of the extended period, with highs in the 30s to 40s. An active pattern will continue beyond then, with a weak wave producing some light precipitation on Saturday morning. Based on temperature profiles, some light wintry mix appears possible, but confidence in any specific precipitation type remains low. The greatest forcing appears likely to remain south of the region. Another strong low pressure system appears likely to move through the Great Lakes and Ohio Valley regions on Monday into Tuesday of next week. While confidence is low in any specifics, a period of warmer temperatures heading into Monday is almost certain, and some windy conditions will yet again be possible. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... Complex TAF over the next 24-30 hours with multiple factors resulting in restrictions across the area. Quiet start to the period still expected as mid-level clouds increase and winds decrease. Between 04-06Z, scattered showers begin to develop and gradually increase in coverage. Still expect some thunderstorm activity with this elevated activity, however, location and duration decreased confidence enough to avoid a mention in the 00Z TAF. After several hours of showers, MVFR CIGs become more likely ~10Z with more widespread MVFR and IFR CIGs developing through 12-15Z. Heavier downpours will lead to MVFR restrictions at times. Additionally, MVFR to IFR BR is possible along the front for a couple hours as it moves slowly northward. Visibility restrictions due to FG are more uncertain with time and space, but with the low- level convergence along the front, it does remain a possibility. Surface flow is east-southeasterly through 14Z, but flow will become more southwesterly as the front pushes north after 14Z, affecting CVG/LUK first (~16Z), then ILN (~18Z), and DAY/CMH/LCK (~20Z-21Z) last. LLWS will be strongest and more persistent north of the surface boundary due to the lower winds. South of the boundary, wind gusts between 30-35 knots will be more likely as the strong low level winds are felt at the surface (decreasing LLWS impacts). These conditions associated with the boundary move north between 15Z-20Z. By 21Z, all sites should be experiencing southerly flow and improved CIGs/VIS. Improvement in CIGs are temporary between 20-24Z with northern sites (DAY, CMH, LCK) least likely to see a complete break in restrictions. Another band of showers and perhaps a few strong wind gusts between 25-40 knots moves through the are between 00Z-04Z Thursday. MVFR CIGs/VIS also possible with this period of activity. .OUTLOOK...Wind gusts up to 45 knots are possible on Thursday. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...Wind Advisory from 11 AM Wednesday to 1 AM EST Thursday for OHZ060>062-070>072-077>079. KY...Wind Advisory from 11 AM Wednesday to 1 AM EST Thursday for KYZ089>098. IN...Wind Advisory from 11 AM Wednesday to 1 AM EST Thursday for INZ050-058-059-066-073>075-080. && $$ SYNOPSIS...Coniglio NEAR TERM...Coniglio/McGinnis SHORT TERM...Coniglio LONG TERM...Hatzos AVIATION...McGinnis
Area Forecast Discussion
National Weather Service Jacksonville FL
838 PM EST Tue Feb 21 2023 ...New UPDATE... .UPDATE... Issued at 835 PM EST Tue Feb 21 2023 Current forecast was on track. A 1019 mb surface high pressure was analyzed off the southwest coast of FL, with our local flow remaining southwest in the low levels. Dewpoints are in the lower 60s with temps in the 70s. Latest satellite imagery shows mainly broken coverage of high clouds, and the beginning stages of low stratus forming over the FL Big Bend area per latest GOES fog channel. Ceilings there are about 900 ft but visibility is still good. With time tonight, the low ceilings will spread east to northeast and visibilities will drop to less than 5 miles at times after midnight, with areas of dense fog possible at or below half a mile. The dense fog chances are greatest, generally from the I-75 and I-10 corridors southward, with some enhanced probabilities spread out southeastward toward Clay, Putnam, southern St Johns and Flagler. This is where the boundary layer winds are weakest. The wind flow may be light enough for some fog and low clouds to push into the nearshore northeast FL coastal waters as well. With the clouds and the south-southwest flow, low temps will again be above normal in the upper 50s to around 60. For the marine forecast update, not much change other than to tweak seas a bit down for tonight, and include some patchy fog wording for Wednesday morning. && .SYNOPSIS... Issued at 512 PM EST Tue Feb 21 2023 Late afternoon surface analysis depicts weakening high pressure (1019 millibars) centered over southeast FL. Meanwhile, a frontal boundary that extends from the Ozarks eastward across the Tennessee Valley and the Carolinas was in the process of stalling. Aloft...stout ridging centered over western Cuba continues to direct shortwave energy eastward from the Upper Mississippi Valley across the Great Lakes and New England. Meanwhile, cutoff troughing spinning over Baja California and the Desert Southwest was poised to pivot northeastward. A stratus deck that resided south of the Interstate 10 corridor this morning has since lifted to a cumulus and stratocumulus deck, while the southern edge of a cirrus shield that was streaming across the southeastern states has also invaded our skies. A tight pressure gradient continues across our area, resulting in breezy west-southwesterly winds area-wide that has allowed temperatures to soar into the 80s all the way to coastal locations this afternoon. A few occasional sprinkles have been noted this afternoon beneath a slightly thicker stratocumulus field over the northern Suwannee Valley and inland southeast GA. Temperatures climbed to the upper 70s and lower 80s this afternoon region-wide despite the multi-layered cloud cover in place across our area. Dewpoints have risen to the upper 50s and lower 60s at most locations. && .NEAR TERM... (Tonight and Wednesday) Issued at 512 PM EST Tue Feb 21 2023 High pressure will continue to shift eastward, merging with a larger Atlantic ridge that resides to the south and southwest of Bermuda by Wednesday afternoon. This evolution of the weather pattern should allow our local pressure gradient to gradually loosen overnight, setting the stage for a round of low stratus ceilings and dense fog to overspread our area from southwest to northeast overnight through the early morning hours on Wednesday as mid and high altitude cloudiness decreases later this evening. Low level southwesterly winds may remain elevated just enough for less fog coverage over southeast GA, with low stratus ceilings expected to overspread areas north of I-10 during the predawn hours. Dense fog is are more likely for locations south of the I-10 corridor, with stratus initially advecting northeastward from Apalachee Bay and the FL Big Bend/Nature Coast shortly after midnight, with fog potentially reaching the I-95 corridor in northeast FL before sunrise. Lows will only fall to the upper 50s and lower 60s at most locations. Ridging aloft will continue to build northward over our region on Wednesday, with rising heights aloft and prevailing southerly low level flow resulting in the first of several days in a row of near record high temperatures (see Climate Section below for details). Fog and low stratus will erode from southeast to northwest during the mid and late morning hours, with mostly sunny skies by early afternoon boosting highs to the mid and upper 80s at most inland locations. Our local pressure gradient should remain just loose enough for the Atlantic sea breeze boundary to develop and move onshore during the mid to late afternoon hours, which should keep coastal highs mostly in the lower 80s. && .SHORT TERM... (Wednesday Night through Thursday Night) Issued at 512 PM EST Tue Feb 21 2023 Stout ridging aloft will deflect the aforementioned cutoff trough currently residing over the Desert Southwest quickly northeastward, with this trough filling as it accelerates across the Ozarks, Tennessee and Ohio Valleys. This trough will subtly change our low level winds from southerly to southwesterly on Wednesday night and Thursday. Another round of widespread stratus and potentially dense fog will again advect across our area during the predawn and early morning hours on Thursday, with inland areas west of the I-95 corridor more favored for dense fog potential. Lows on Wednesday night will remain in the lower 60s at most locations, with highs on Thursday soaring to the upper 80s at inland locations, with coastal highs climbing to the low and mid 80s. SREF probabilities for fog and low stratus ceilings remain rather high for late Thursday night and Friday morning, and lows will again only fall to the 60-65 degree range at most locations. && .LONG TERM... (Friday through Monday) Issued at 512 PM EST Tue Feb 21 2023 Stout ridging in place over the FL peninsula on Friday will gradually flatten and will begin retrograding slowly westward across the Gulf of Mexico, allowing a weakening cold front to push across southeast GA on Friday afternoon and evening. Support aloft for this front will be minimal, with only isolated showers possible ahead of this boundary on Friday afternoon and evening, mainly for locations north of Waycross in southeast GA. Near record warmth will otherwise continue on Friday, as inland highs again soaring to the mid and upper 80s, while an afternoon sea breeze keeps coastal highs in the lower 80s. The front will stall near the FL/GA border by late Friday night, Lows will continue to range from 60-65 degrees. Strong high pressure building over New England on Friday in the wake of this frontal boundary will quickly weaken as it slides southeastward and off the Mid-Atlantic coast by Saturday night. This feature will briefly wedge down the southeastern seaboard on Saturday, with onshore winds developing, keeping coastal highs in the 70s for locations north of St. Augustine. Inland highs on Saturday will cool slightly to the lower 80s for inland southeast GA, while unseasonably warm weather continues for northeast and north central FL, where highs will again reach the mid to upper 80s. Breezy southwesterly winds will again develop on Sunday as the front lifts back to the north as a warm front, with highs again climbing well into the 80s area-wide on Sunday and Monday ahead of an approaching cold front that should enter the southeastern states towards Monday evening. Lows will continue to run well above average, with upper 50s and lower 60s continuing into early next week. && .AVIATION... (00Z TAFS) Issued at 645 PM EST Tue Feb 21 2023 VFR this evening with FEW-SCT cumulus and high clouds. Fairly moist, southwest flow and overnight cooling will lead to some low clouds overnight. First site to be affected should be GNV then VQQ with the flow off the Gulf of Mexico bringing clouds to the inland northeast FL area. Confidence in low clouds forming is high, but details on the extent and duration is more uncertain, with the HRRR model suggesting the IFR and potential LIFR will oscillate to some extent early in the morning hours, though less so at GNV. Overall, slightly lower chance of LIFR and IFR for JAX/CRG/SSI, but still higher confidence in at least IFR CIGS at these locations. Lowest vsby looks to be around VQQ, GNV, and SGJ. Cig/vsby conditions should improve between 14z-16z, with VFR clouds after 16z. Sfc winds will be light southwest tonight, and then become south-southwest 6-12 kt on Tuesday after 15z, with some gusts to about 20 kt Tuesday aftn. Slight backing of winds expected for SGJ and SSI due to the aftn sea breeze. && .MARINE... Issued at 512 PM EST Tue Feb 21 2023 High pressure centered over southeast Florida will shift eastward tonight, moving east of the Bahamas by Wednesday morning. Breezy west southwesterly winds sustained around 15 knots this evening will gradually diminish after midnight. Seas will subside to 2-3 feet both near shore and offshore overnight. Prevailing winds will become southerly on Wednesday and Thursday, with an evening wind surge expected offshore on Wednesday evening. Speeds should reach Caution levels of 15-20 knots offshore before diminishing after midnight, resulting in seas briefly building to 3-5 feet. A weakening cold front will then approach our local waters on Friday evening. This boundary will likely stall over the northeast Florida waters by late Friday night and Saturday before lifting northeastward as a warm front on Saturday night. Winds will briefly become onshore on Friday night and Saturday, shifting to southerly and then southwesterly late in the upcoming weekend through Monday. A longer period northeasterly ocean swell will arrive over our waters this weekend, likely resulting in seas building to 3-5 feet both near shore and offshore. A cold front is then expected to approach our local waters next Tuesday, accompanied by scattered showers. Rip Current Risk: Breezy south-southeasterly winds developing behind an inland moving Atlantic sea breeze boundary on Wednesday afternoon may create a low-end moderate risk at the northeast FL beaches. Prevailing south-southwesterly winds should keep the risk low at area beaches on Thursday and Friday. && .FIRE WEATHER... Issued at 512 PM EST Tue Feb 21 2023 Gusty west-southwesterly surface and transport winds will gradually subside overnight, but transport speeds will remain sustained at 5-10 mph, keeping nighttime dispersion values slightly elevated. Surface and transport winds will then shift to southerly after sunrise on Wednesday, with breezy conditions developing during the mid-morning hours as low clouds and fog dissipate. These breezy conditions will create good dispersion values area-wide, with some marginally high values possible for areas along the U.S. Highway 301 corridor during the afternoon hours. The Atlantic sea breeze will develop and move onshore at coastal locations during the afternoon, resulting in breezy southeasterly surface winds for locations east of I-95. Breezy southwesterly surface and transport winds are expected after sunrise on Thursday, creating good daytime dispersion values area- wide again. Lighter west to west-northwesterly surface and transport winds are forecast on Friday. && .HYDROLOGY... Issued at 512 PM EST Tue Feb 21 2023 Water levels along the Alapaha River near the Statenville gauge will crest in a minor flood on Wednesday, followed by water levels falling below flood stage by early Friday morning. Otherwise, minor flooding will continue through Thursday along upper portions of the Altamaha River. Minor flooding will also continue through the upcoming weekend along lower portions of the Satilla River near the Atkinson gauge. && .CLIMATE... Issued at 512 PM EST Tue Feb 21 2023 Daily record high temperatures from Wednesday through Friday at our designated climate sites: Wed 2/22 Thurs 2/23 Fri 2/24 Sat 2/25 Sun 2/26 -------------------------------------------------------- Jacksonville 87/2019 85/1962 88/1962 87/2022 88/1962 Gainesville 88/2019 91/2019 88/1962 82/2022 88/1971 Alma, GA 84/2019 84/2018 85/2018 83/2001 82/1996 St. Simons Island 81/2011 82/2012 84/2012 80/2022 83/1972 Craig Airport 86/2019 85/2012 86/2012 85/2018 85/2018 All-time records for the month of February at our designated climate sites: Jacksonville 89 2/13/2020 Gainesville 91 2/23/2019 Alma, GA 87 2/21/2018 St. Simons Island 85 2/28/1962 Craig Airport 87 2/18/2021 && .PRELIMINARY POINT TEMPS/POPS... AMG 60 85 62 86 / 0 0 0 0 SSI 60 80 62 81 / 0 0 0 0 JAX 59 86 61 88 / 0 0 0 0 SGJ 60 83 62 84 / 0 0 0 0 GNV 58 86 60 86 / 0 0 0 0 OCF 58 87 60 87 / 0 0 0 0 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. && $$
Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
540 PM CST Tue Feb 21 2023 ...Aviation Update... .SYNOPSIS... Issued at 347 PM CST Tue Feb 21 2023 H5 analysis from this morning has a very active pattern across the CONUS and Canada. Starting in the west, closed low pressure was located along the Baja California coast. A strong shortwave trough was located off the coast of British Columbia. Several embedded shortwaves extended east southeast of this feature into Washington State, Montana, northern Wyoming and the Dakotas. Further east, closed low pressure was located over Hudson Bay. A shortwave trough extended from south central Ontario into the upper Ohio Valley. At the surface, low pressure was located over northwestern South Dakota. A warm front extended east southeast of this feature into far northeastern Nebraska. A surface trough extended south of this low into eastern Colorado. Along and north of the warm front, bitter cold temperatures were noted along with ongoing snowfall. South of the front, winds were southerly this afternoon and 2 PM CT readings were in the middle 30s to middle 40s. Key Messages: - A winter storm is likely tonight through Thursday morning across the central Sandhills, north central Nebraska and the eastern Nebraska Panhandle. - Bitter cold wind chills are likely Thursday morning and may approach 40 below zero in some areas. - Another storm may impact the area Sunday night into Monday, with the possibility of rain/snow and strong winds. && .SHORT TERM...(This evening through Wednesday night) Issued at 347 PM CST Tue Feb 21 2023 A strong arctic cold front will track through the area tonight, clearing the forecast area by 12z Wednesday. Behind the front, mid level warm air advection will spread from Wyoming into western and north central Nebraska overnight into Wednesday. Light snow will develop overnight in the northwest and spread south into the western and central Sandhills and north central Nebraska. Persistent light to moderate snow will continue during the day on Wednesday as mid level warm air advection continues. Across southwestern Nebraska, very light snow will develop later on Wednesday. Accumulations south of a line from Grant, to North Platte to Broken Bow will be very light Wednesday with accumulations in these areas generally under an inch. Snowfall rates will then increase Wednesday evening from southwestern into central and north central Nebraska as a strong mid level disturbance approaches the area from the southwest. Snow totals trended down in southwestern Nebraska with the inherited forecast this morning and this forecast cycle`s WPC QPF numbers were half of the pvs. forecast from overnight. For LBF, the WPC numbers were around 0.12 inches which was below the inherited forecast (~0.20 inches) and well below the ensemble means from the GFS and EC solns (~0.25-0.30 inches). The latest NAM12 and HRRR solns did work in more mid level drying in association with the Wednesday evening shortwave, which did lead to lower QPF`s for these solns. This resulted in the lower model blend QPF with this forecast cycle. With this package, went ahead and lowered QPF slightly from the ensemble forecasts, but not nearly as low as the WPC forecast. This yielded snow totals on the order of 1 to 4 inches in the advisory area and 4 to 12 inches in the warning area. Strong cold air advection tonight through the first half of Wednesday, will facilitate gusty northerly winds with this system. A secondary shot of gusty winds will arrive Wednesday evening into Thursday as strong surface low pressure tracks along the arctic front from southern Kansas into northwestern Missouri. The combination of winds and bitterly cold temperatures of -5 to -15 degrees will push wind chills to -25 to -40 by Thursday morning. Current winter headlines for snow and blowing snow run until 12z Thursday morning. Will possibly need to extend a winter storm warning for the northeastern zones to noon Thursday, given the blowing snow threat. For the entire forecast area, wind chill headlines will eventually be piggy backed on existing winter headlines. Until timing becomes more certain and the blowing snow threat is better handled, will hold off on any wind chill headlines with this package. .LONG TERM...(Thursday through Tuesday) Issued at 347 PM CST Tue Feb 21 2023 Surface high pressure (~1040+ MB) will build into the eastern Dakotas Thursday night. Winds will be much lighter Friday morning, however temps may end up being colder, particularly over the northeastern forecast area in closer proximity to the high. As for wind chills, even with the lighter winds, they will bottom out in the -20 to -30 degree range. A weak mid level disturbance will ride east of the Rockies Thursday night into Friday. Decent mid level warm air advection will overspread the central and southern Plains Thursday night into Friday. However, moisture will be limited in the wake of the Wednesday weather system. The latest EC soln does generate some light precipitation in eastern Nebraska. The latest NBM does have some limited pops in eastern Nebraska and this appears plausible based on the latest EC and GFS solns. Warmer temperatures will return to the area Saturday and Sunday with highs in the 40s. A strong upper level low will approach the central and southern plains from the Four Corners Sunday. Low pressure will rapidly deepen over eastern Colorado Sunday with strong southerly winds increasing into the afternoon hours. Low level moisture advection will increase quickly from Kansas into central and eastern Nebraska with EC and GFS surface dew points reaching the upper 30s to mid 40s by 00z Sunday. Further south, convection may fire across western Kansas INVOF the dryline and surface warm front. As this convection races northward into Nebraska, we may see rain over snow covered areas. This could lead to some runoff issues, particularly in the eastern half of the forecast area. We will need to monitor this closely over the next few days, as there could be an increased threat for flooding issues if rainfall rates and rain duration are high enough over snow covered-frozen ground. With respect to severe storms, the latest day 6 SPC outlook has a 15 percent severe risk right up to the NE/KS border (south central Nebraska). If this remains in place, feel the threat for showers embedded thunderstorms will increase for the eastern forecast area. Right now, will leave out the mention of thunder with this forecast package. One aspect with this storm system which seems fairly certain is the wind potential. Both the EC and GFS solns, develop a sub 985mb low over Kansas, approaching 980mb as it lifts east Sunday night. This would lead to very strong winds on the back side of this system Sunday night into Monday. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 539 PM CST Tue Feb 21 2023 MVFR/IFR/local LIFR ceilings and vsbys are likely overnight and Wednesday. This flight concern will commence with the passage of an arctic cold front moving steadily south through the cntl high Plains. IFR/LIFR is expected to become widespread along and north of highway 20 where snow is most likely to occur. && .LBF WATCHES/WARNINGS/ADVISORIES... Winter Storm Warning from midnight CST /11 PM MST/ tonight to 6 AM CST /5 AM MST/ Thursday for NEZ004>010-022>029-035>037-056- 057-094. Winter Weather Advisory from midnight CST /11 PM MST/ tonight to 6 AM CST /5 AM MST/ Thursday for NEZ038-058-059-069>071. && $$ SYNOPSIS...Buttler SHORT TERM...Buttler LONG TERM...Buttler AVIATION...CDC
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
908 PM CST Tue Feb 21 2023 .UPDATE... Issued at 905 PM CST Tue Feb 21 2023 We will not be making any big changes to the forecast this evening given the lack of observational evidence to steer the ship on a different course, though it is a challenging forecast as we head into Wednesday. It`s pretty tough to ignore some of the earlier guidance from our freezing rain accumulation models putting out some significant ice accumulations coupled with a decent winds, and also a signal in some recent CAM runs of even some icing potential into the Chicago metro area with the first precipitation surge in the morning. But looking at the big picture, temperatures have been holding steady this evening across the area even as dewpoints rise. Forecast soundings depict a fairly warm layer aloft will be advecting in later tonight and tomorrow. Meanwhile, the low level cold layer does not appear to be deep enough to support too much in the way of sleet. Without a significant surge of cold air, we will need some wet-bulbing to bring temperatures down over the metro area. The debate is still on as to how much precipitation will be occurring into the colder air mass in the morning hours, latest RAP runs and 0z NAM really not that aggressive with the northern extent of heavier precipitation. The heavier rates will becoming in as the warm nose surges farther northward. Our northern tier of counties remain in a precarious position, but at this distance confidence in more impactful ice accumulations is not high enough to steer towards a warning until our midnight shift gets a chance to watch the evolving observational trends and new 0z guidance. KMD && .SHORT TERM... Issued at 315 PM CST Tue Feb 21 2023 Through Wednesday night... Key Forecast Messages and Concerns: * Wintry Mix With Accumulating Ice and Sleet on Wednesday: Winter Weather Advisory issued for areas north of I-88 6 AM Wednesday-6 AM Thursday, with exception of DuPage and northern Cook where confidence is lower in any ice accumulations. Greatest concern for state line counties where ice accumulations of greater than 1/4 inch are distinctly possible and we do have some localized accums up near 0.3". There are competing factors tomorrow and tomorrow night regarding surface temperatures of 32F or lower being realized, accretion efficiency during the highest precip rates Wednesday afternoon, and the mild antecedent conditions plausibly supporting a scenario in which ice accums and impacts are lower. However, on the other hand, can`t ignore the signal from the 12z and new 18z operational models, plus the 12z HREF mean. The overall trend today was for near or below freezing temps to have a farther south footprint. Contemplated going to an Ice Storm Warning for the WI state line counties, but given the concerns about less ice and lower impacts, opted for advisory issuance. The earlier precipitation onset Wednesday morning is now more likely to overlap with temps being near or a bit below freezing near and north of I-88, again with higher confidence well inland of the lake. This was part of the reasoning for including Ogle, DeKalb, and Kane Counties in the WWA. It`s quite possible impacts are limited Wednesday morning and then temps warm above freezing, but admittedly confidence is low in the exact 2m temps. Then on Wednesday evening when precip rates diminish, the winds will shift to more northeast or north-northeast from east-northeast during the day. This could allow for some colder air to bleed south and renewed ice accums down closer to I-88 corridor if plain rain is observed Wednesday afternoon. Given the warm antecedent conditions, any road impacts may be relegated to elevated surfaces until Wednesday evening when accretion rates may improve. For the state line counties, the threat for accums up to 1/4" or a bit more does introduce a higher threat for tree damage, ice accums on powerlines, and power outages, also taking into account the northeasterly winds gusting up to 35 mph. Finally, yet another potential "fly in the ointment" is accumulating sleet, owing to likely embedded convective elements, plus low level cold wedging (with model variance on magnitude of this). Should sleet overperform, there is a threat for accums nearing 1/2" closer to the WI state line. Given all of the counteracting points of uncertainty tomorrow, despite plausible threat for more widespread ice accums greater than 1/4" along WI state line, opted with this issuance for the WWA and will let midnight shift consider whether an upgrade to Ice Storm Warning is warranted. * Heavy Rainfall and Embedded Thunderstorm Threat on Wednesday: The 350-400% of normal PWAT plume potentially upwards of 1.3" (at or above Feb max for ILX) will surge northward on Wednesday amidst strong large scale ascent from upper jet dynamics and a stout positively tilted mid-level short-wave and speed max. This will be juxtaposed with a potent low-mid level baroclinic zone draped across the region. Finally, the anomalous warmth associated with the moist plume can be expected to steepen lapse rates enough for isolated to scattered embedded thunderstorms mid day Wednesday through early evening, particularly near and south of I-88/290. Due to the above factors, rainfall, heavy at times, is expected on Wednesday afternoon across most of northeast Illinois and northwest Indiana. Local areas may receive rainfall heavy enough to cause river rises, widespread ponding of water, and localized flooding. 6-hour rainfall amounts of 1 to 1.5" are forecast in the heaviest swath from noon to 6pm on Wednesday. While a slight southward shift was noted in the 12z guidance and ensemble means, the threat for very heavy rainfall does extend into the southeast 1/2 or so of the Chicago metro and points south and southeast. The 12z HREF probability matched mean indicates threat for a localized corridor of 2-3" amounts, though confidence is lower end in occurrence and the exact location of this localized corridor of heavy rain. Latest trends suggest relative threat zone for this corridor of higher amounts is near and southeast of I-55 down to the US-24 corridor (and we do have isolated spots of just above 2" event total QPF in the gridded forecast). Soil moisture ranges from near average in east central Illinois to above average in northern Illinois. Most area soils have no remaining frost depth except for the headwaters of the Fox and Rock rivers in southern Wisconsin. All snow cover has melted due to recent mild temperatures. The lack of snow cover and frozen soils may somewhat reduce the risk of more impactful flooding, but this may be balanced out by the expected heavy rainfall rates, elevated soil moisture, and lack of evapotranspiration. The current forecast of 1 to 2 inches of rainfall would likely cause several area rivers, including the Little Calumet, Kankakee, Iroquois, Fox, and Illinois, to near or exceed bankfull levels. With the off the charts moisture parameters, but key points of uncertainty (exact location of heaviest rainfall; shorter duration of heavy rates; possibility of true warm sector convection robbing some of the moisture transport; and lack of river ice and frozen grounds), opted to re-issue the ESF focused south of I-88. May need to consider a targeted Flood Watch if confidence increases in the 2-3" rainfall corridor through Wednesday afternoon, which would increase the chance of more than minor flooding/road ponding type impacts, as 6-hour flash flood guidance is around 2". * Threat for localized thunderstorm wind damage Wednesday in parts of central Illinois into central Indiana: The warm sector south of the sharpening warm front east of developing low pressure on Wednesday will be characterized by temperatures of 55-60F and dew points into the 50s. HREF CAM guidance depicted a scenario in which small convective segments aided by gravity wave propagation may yield localized corridors of damaging winds. Confidence is low in how far north this threat will extend, with south of US-24 currently the area of greater concern. SPC did expand the day 2 "marginal" (level 1 of 5) risk to include parts of central IL into IN. Officially this clips southern Ford County. This will certainly be something to monitor, plus low CAPE, high shear cold season set-ups also bare close monitoring for brief fast-moving tornadoes. Castro && .LONG TERM... Issued at 253 PM CST Tue Feb 21 2023 Thursday through Tuesday... By Thursday morning, the storm will have just about cleared the area. A secondary low pushing across the CWA is expected to have some stratiform precip riding its northern flank, some of which may fall on the northern part of the area through the morning. With very shallow saturation, any precip that does fall should be very light. Thermal profiles from forecast soundings would suggest primarily rain, though some snow may get mixed in there if we can saturate deep enough to introduce some cloud ice. Otherwise, Thursday will likely be dry across most of the area. Once that center of low pressure passes off to the northeast, a tight surface pressure gradient and a stout low level jet moving over will drive winds up through the morning. Late morning through early afternoon looks to be the timeframe of the strongest winds when we could be gusting upwards of 40+ kt. The depth of the mixing layer is in fairly good agreement, as are the steep lapse rates through the mixed layer suggesting efficient mixing down of winds through the channel. The strength of the LLJ is where most of our discrepancies are rooted with guidance throwing up anywhere from 35 to 55 kt at 925mb. There appears to be good clustering of models around the 40 kt range. Additionally, it appears models have been on a modest downward trend for Thursday`s winds since yesterday`s 00Z runs. Gusts will slowly creep down through the evening and overnight. A high nearing the area to the northwest will drive some cooler air in here for Thursday night and Friday. Lows early Friday morning are forecast in the teens with morning wind chills as low as a few degrees below zero near the IL/WI stateline to single digits across most of the CWA. Highs on Friday look to be capped in the middle 20s to lower 30s. Friday evening and night, a low amplitude shortwave will interact with ample low and mid level moisture to provide a chance for a few light snow showers. Both the GFS and Euro are throwing up a few tenths of an inch of accumulation. Veering winds through Friday night will result in efficient low level WAA heading into Saturday pulling Saturday afternoon highs into the upper 30s and 40s. This warming trend will continue through the weekend with a ridge building aloft Sunday into Sunday night. Highs on Monday look like upper 40s in the north to near 60 degrees in the far southern CWA. On Monday, behind the aforementioned ridge, a trough will be swinging into the Midwest that looks to drop another healthy storm system. The GFS is the most aggressive with this trough actually resolving an upper low whereas the Euro and Canadian like the idea of a low-amplitude, negatively-tilted trough. Nonetheless, all three models place a speedy jet max on the trough`s leeward side whose nose moves right across central IL and resolve a widespread rain event for Monday. An early thunderstorm threat also exists with guidance throwing up a couple of hundred joules of CAPE. If the Euro and Canadian`s negative tilt plays out, resultant steep lapse rates carry the thunderstorm chances even further. However, while there`s surprisingly good agreement on this potential storm system, it`s still far too early to get excited about any thunder chances. Doom && .AVIATION... For the 00Z TAFs... 547 PM...Primary forecast concerns include... Freezing rain Wednesday northwest IL, including RFD. Lifr, possible vlifr, cigs/vis Wednesday/Wednesday evening. Strong/gusty northeast winds Wednesday/Wednesday night. Light winds to start will become easterly over the next few hours with speeds increasing to 10-15kts tonight with gusts into the 20 kt range possible by the predawn hours. Winds will turn northeast Wednesday morning with gusts increasing into the mid/upper 20kt range. Winds are expected to remain northeast for the terminals into Wednesday night, though speeds/gusts will likely slowly diminish Wednesday evening. Light rain is expected to spread across northern IL around/just after daybreak Wednesday morning. There is some concern for a brief period of freezing rain/sleet when this precip begins, especially for ORD/DPA. Confidence is fairly low and for now have maintained liquid rain. Rain will continue through late Wednesday afternoon and the rain may be heavy at times, especially for MDW and GYY. There may also be a few thunderstorms, especially south of the terminals and confidence for thunder at MDW/GYY is too low to include in this forecast. The rain is expected to taper off to showers or drizzle early Wednesday evening. At RFD, precip is expected to start as freezing rain and its likely freezing rain will continue through much of the afternoon with perhaps light rain or drizzle as the precipitation ends, though light freezing rain or light freezing drizzle may continue into Wednesday evening. There may also some sleet mixed in at times at RFD, but confidence is also low. Cigs will remain vfr until the precipitation arrives and then cigs are expected to quickly lower through mvfr, then ifr with lifr and possibly lifr cigs expected Wednesday afternoon into Wednesday evening. cms && .MARINE...Updated at 358 PM CST Tue Feb 21 2023 Hazardous east-northeast winds and associated waves will develop tonight into Wednesday north of a developing low pressure system. Brisk northeast winds may flirt with gales over parts of the Illinois nearshore late Wednesday-Wednesday evening, though confidence remained too low for watch issuance. Then on Thursday, there`s increasing confidence in and likelihood of gale force gusts up to 40 kt as secondary low pressure quickly lifts to the northeast. A Gale Watch was issued for this period (in effect from 9 AM to 9 PM Thursday for the entire IL/IN nearshore), with the highest speeds/gusts mid day Thursday through early Thursday evening. KJB/Ogorek/Castro && .LOT WATCHES/WARNINGS/ADVISORIES... IL...Winter Weather Advisory...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008- ILZ011-ILZ012...6 AM Wednesday to 6 AM Thursday. IN...None. LM...Gale Watch...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...9 AM Thursday to 9 PM Thursday. Small Craft Advisory...LMZ740-LMZ741-LMZ742...midnight Wednesday to 3 AM Thursday. Small Craft Advisory...LMZ743-LMZ744-LMZ745...midnight Wednesday to 9 PM Wednesday. && $$ Visit us at Follow us on Facebook, Twitter, and YouTube at:
Area Forecast Discussion
National Weather Service Melbourne FL
908 PM EST Tue Feb 21 2023 ...New UPDATE, MARINE, AVIATION, PREVIOUS DISCUSSION... .UPDATE... Through tonight...What little diurnal SCU formed this afternoon rapidly dissipated around sunset, leaving thin high clouds to stream overhead, much like last night. With the surface and low level ridges starting to creep northward, conditions appear a little more favorable for fog to form over the peninsula. We`lll likely see it initially to our west, spreading east in prevailing west low level-flow. Inherited forecast has this trend well in hand. made some cosmetic changes to the grids (mainly sky cover), but nothing that would require a ZFP update. && .MARINE... Issued at 908 PM EST Tue Feb 21 2023 Tonight...West winds will slowly back to SW overnight as the surface ridge axis lifts north toward Lake O and the adjacent Atlantic. Speeds AOB 10kt, seas 1-2ft near shore/2-3ft offshore. && .AVIATION... (00Z TAFS) Issued at 908 PM EST Tue Feb 21 2023 Little change to the afternoon package showing developing of fog stratus. Some "pessimistic" adjustments toward prevailing IFR/LIFR may become warranted later tonight, as the HRRR continues to show, We`ll see if this is a function of its overaggressive bias with low VSBYs, however there is better support from MOS guidance for dense fog compared to last night. && .PREV DISCUSSION... Issued at 237 PM EST Tue Feb 21 2023 ...Near Record Warmth for the Next Several Days... Wednesday...Mid-level high pressure ridge will dominate the local area, which will produce strong subsidence aloft, leading to dry conditions and warm-hot afternoon temps. Highs will be near records, mainly across the interior due to the sea breeze providing some relief for coastal areas. Afternoon highs will be in the upper 80s west of I-95, and mid 80s near the coast with plenty of sunshine through the day. However, upper 80s would occur inland from the barrier islands should the sea breeze be slower to form/push inland. Wed Night-Tue...Very warm and dry conditions will prevail across the area through the next several days, as mid-level ridge dominates the weather pattern across Florida. Highs will be near record values, mainly across the interior, as highs reach the U80s each day, and even near the 90 degree mark on Thu. At the coast, highs will generally range from the L-M80s as the sea breeze should form each afternoon and provide some relief. However, U80s are not out of the question for coastal locations (excluding the barrier islands) should the sea breeze be slower to move inland, which could be the case on Wed-Thu. The NBM has backed off some on showing highs reaching the 90-degree mark across the interior into late week and weekend, except on Thu. MOS guidance also keeps max temps below this threshold as well, but has also been a little too low compared to observed values the past couple of days. However, should highs reach 90 degrees or L90s, this will not only break daily record highs but also threaten record highs for the month and Winter Season (see climate section below for values). Temperatures will remain mild, with overnight lows in the L-M60s, potentially falling into the U50s for some areas on Sat and Sun nights. However, no daily warm minimum temperature records look to be reached. && .MARINE... Issued at 237 PM EST Tue Feb 21 2023 Wednesday...Generally good boating conditions. West winds will back during the afternoon as the sea breeze develops with winds generally 10-15kt. Seas 2-3ft. Wed Night-Sun...High pressure over the west Atlc will allow winds to become more southerly over the waters thru Thu, generally around 10- 15 kts, except up to 15-20 kts Wed night. Winds diminish to 5-10 kts and become a little more variable in direction Fri before becoming more S/SE on Sat as a weak back door front nears the offshore waters. Seas will range from 1-3 ft, except up to 4 ft offshore Wed night. && .FIRE WEATHER... Issued at 237 PM EST Tue Feb 21 2023 High pressure will continue to dominate the local weather this week, which will lead to no mentionable rain chances and warming temperatures. Near record highs will be possible this aftn along the east coast, then focusing on the interior later in the week. Min RH values will remain above critical levels, but the extended heat and dryness should start to increase wildfire potential. Dispersion values will be Very Good this aftn and Wed. && .CLIMATE... Issued at 237 PM EST Tue Feb 21 2023 Near record highs are expected over the next several days, especially along the coast this aftn, and then focused across the interior from Wed-Sat. Highs near the 90 degree mark are possible across the interior from mid-week into this weekend, especially on Thu, which could tie or potentially break record highs for the month and even the Winter Season! Daily Record Highs For the Next 5 Days (Through the 2/25): 21ST 22ND 23RD 24TH 25TH LOC HI-MAX HI-MAX HI-MAX HI-MAX HI-MAX DAB 87 1989 87 1962 87 2013 88 2012 87 2022 LEE 87 2018 89 1991 87 2019 87 2012 88 2022 SFB 87 2003 88 2003 88 2019 89 2012 89 1962 MCO 88 1989 88 2003 89 2013 90 1962 90 1962 MLB 88 1989 88 2003 90 1961 92 1962 87 2013 VRB 87 2014 89 2003 89 2008 90 2019 87 2020 FPR 89 1989 89 2003 89 1932 90 2012 87 2020 Record Highs for the Month of February and for the Winter Season (Dec-Jan-Feb) and dates of last occurrence: LOC FEB HI-MAX WINTER HI-MAX DAB 89 02/01/1985 89 02/01/1985 LEE 89 02/22/1991 89 02/22/1991 SFB 89 02/24/2012 89 12/18/2016 MCO 90 02/25/1962 90 12/07/1978 MLB 92 02/24/1962 92 02/24/1962 VRB 90 02/24/2019 90 02/24/2019 FPR 90 02/24/2012 90 02/24/2012| && .PRELIMINARY POINT TEMPS/POPS... DAB 59 84 62 85 / 0 0 0 0 MCO 61 88 64 90 / 0 0 0 0 MLB 61 84 63 85 / 0 0 0 0 VRB 60 85 63 85 / 0 0 0 0 LEE 61 87 64 89 / 0 0 0 0 SFB 59 88 63 89 / 0 0 0 0 ORL 62 88 65 90 / 0 0 0 0 FPR 62 84 65 85 / 0 0 0 0 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. && $$ SHORT TERM...Cristaldi LONG TERM....Smith AVIATION...Cristaldi
Area Forecast Discussion
National Weather Service Pueblo CO
648 PM MST Tue Feb 21 2023 .UPDATE... Issued at 639 PM MST Tue Feb 21 2023 Main updates this evening were to allow the High Wind Warning across the Sangre de Cristo mountains and Red Flag Warning across the southeast plains expire this hour. RH values will continue to quickly improve, while winds diminish. Some guidance hinting that the winds will remain elevated for a few more hours this evening over the far southern Sangres, with isolated gusts potentially in the 50 to 70 mph range. At this time, coverage and duration are not expected to be high enough to warrant extending the High Wind Warning. No other big changes planned for this evening at this time. Am concerned for fire danger returning Wednesday afternoon over the far southern I-25 corridor and southeast plains, south of Highway 50. With deep mixing expected tomorrow, temps in the warm sector have the potential to rise to around 60 while dewpoints fall to the lower teens. This will support RH values in the 15 to 20 percent range, however, winds will likely be gusting up to around 65 mph during this time. So, while confidence is not high enough to issue a Red Flag Warning at this time, will trend the forecast towards this possibility as well as likely message the possibility for near critical fire weather conditions. && .SHORT TERM...(This evening through Wednesday) Issued at 334 PM MST Tue Feb 21 2023 Key Messages: 1) Strong winds over the east slopes of the Sangres will persist into early evening before diminishing 2) Heavy snow and strong winds hit the Continental Divide overnight 3) Strong/damaging winds south of Highway 50 on Wednesday, heavy snow and wind continue along the Divide 4) Quick burst of rain/snow showers I-25 corridor and plains Wed afternoon as upper trough moves across. Currently...Downslope winds howling over the lee slopes of the Sangres this afternoon, with numerous gusts in the 80-90 mph range west of Westcliffe. Not quite as windy elsewhere, though still plenty of gusts in the 40-60 mph range at many locations, and Red Flag Warning was verifying with very low humidity over the far southeast plains. Webcams suggest snow has yet to start along the Continental Divide, though areas of blowing snow were noted over the higher peaks. Tonight...Main upper trough digs into the Great Basin as 140 kt jet streak punches eastward through AZ. Expect snow to increase quickly along the Continental Divide overnight, especially over the eastern San Juans, where snowfall rates of up to 3 inches per hr will be possible by early Wed morning. Elsewhere, snow showers will reach the Sangres by sunrise Wed, with some light snow in most interior valleys as well. Winds will diminish overnight, and will let High Wind Warning end this evening, as relative lull in mid level winds moves across the region. On the plains, cold front oozes south toward the Arkansas River by early morning, with wrn edge of very shallow cold air likely just west of I-25 in El Paso County, while farther south east winds may at least briefly push westward through Canon City early Wed. Wednesday...Wind and snow increase over the mountains, with whiteout conditions in the San Juans where combination of very heavy snow and strongest winds will occur. Sangres and srn San Luis Valley will also see snow and strong winds develop in the morning, though snowfall rates here will be less. Winds increase further around midday as upper level jet lifts into srn CO, and expect strongest/potentially damaging winds over the Sangres and adjacent lower slopes through the day. On the plains, models still struggling with position of cold front, as HRRR/NAM solutions bring deep mixing eastward off the high terrain and shove the cold air nearly out of srn CO by afternoon. GFS a good deal slower with mixing, though even it has trended farther north with the boundary, lifting it to near the Arkansas River by 00z. We`ll see big temp and wind contrast across the boundary wherever it ends up, with howling w-sw winds to the south, and lighter e-ne winds and clouds to the north. Do expect a quick burst of rain and snow showers to move off the southeast mountains and across the I-25 corridor in the afternoon as strongest upper lift and 700 mb front whip across, and while precip may be fairly intense, it will be moving very quickly and likely not persist more than an hr at most locations. Have thus trended back precip and snow amounts along I-25, and boosted wind speeds in areas that will likely mix in the afternoon. Temps highly dependent on boundary placement, NBM looked like a fairly good solution, so stuck close to it. For highlights, no changes to winter advisories/warnings for tonight and Wed. For high wind, did add the Wet Mountains to the High Wind Warning for Wed afternoon, as downslope wly flow develops and HRRR suggests 60-70 kts possible .LONG TERM...(Wednesday night through Tuesday) Issued at 334 PM MST Tue Feb 21 2023 Key Messages: 1) Light to moderate snow is expected through much of the day Thursday along the mountains. 2) Light pockets of snow along the mountains, mostly central and western mountains, Friday and Saturday. 3) Another system passes over Colorado, bring increased precipitation chances for much of southern Colorado. 4) Next week brings quieter and warmer weather to southern Colorado. Thursday... Active weather is expected for the start of the long term period. Synoptically, a trough is expected to be exiting the region during the AM hours, with strong southwesterly flow developing behind it, which both ensemble and deterministic model guidance support, leading to greater confidence in this pattern evolution. With synoptic support decreasing as the trough exits, any precipitation over the plains and valleys is expected to dissipate during the early AM hours and dry conditions to prevail the rest of the day. With that said though, scattered to widespread pockets of light to moderate snow are anticipated to persist along the mountains, particularly the San Juan Mountains, through the entire day given strong orographic forcing taking place. As for temperatures, a cooler day is expected for much of the region. For areas west of the I25 corridor, despite downsloping winds, cloud cover and fresh snowfall will help to keep temperatures below average for this time of year. Along and east of the I25 corridor is more messy with where the cooler and warmer air will be. A cold front is expected to be draped across the eastern plains Thursday and there is still some uncertainty in regards to the eventual location of this front during the day, which leads to uncertainty to how temperatures will eventually evolve throughout the day. With that said, current thinking is the front will take on a northwestward to southeastward orientation across Pueblo County and down into Baca County. Areas north of this front will be colder, while areas south of it will have downsloping and warmer temperatures. Friday - Saturday... For the end of the week and start of the weekend, a slow downtrend in active weather is expected. Largely, flow will maintain the southwesterly component Friday, with a more ridging pattern Saturday. This pattern will be unfavorable for precipitation across most of southern Colorado both days, and given that, dry conditions are expected. The exception to this will be along the central and western mountains, where pockets of light snow are expected, particularly Friday when orographic forcing will be best. Looking at temperatures, a solid warming trend is expected for much of southern Colorado. Downsloping westerly winds will bring compressional warming each day, with Saturday being the warmest of the two. Sunday... The last day of the weekend brings another system to southern Colorado. Ensemble models are in good agreement about pushing a short wave trough across the southern Colorado region throughout the day Sunday. This wave will increase precipitation chances for the region, but especially along the mountains, where orographic forcing will be taking place. Given the current time of the wave, Sunday will still see a warmer trend, with much of the area still expected to have downsloping westerly winds. This will keep the southern Colorado region above average for this time of year. Monday - Tuesday... Finally into next week, another relatively quieter couple of days is expected for southern Colorado. Ensemble model guidance remains in agreement about the pattern evolution, building a ridge over the Colorado region. Given increasing descent with this feature, which is unfavorable for precipitation, dry conditions are expected for southern Colorado. Despite the short wave from Sunday, both Monday and Tuesday will remain above average for the time of year given, you guessed it, more westerly and downsloping winds inducing more compressional warming for much of the region. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 334 PM MST Tue Feb 21 2023 At KALS, VFR overnight, then vcsh after 10-12z Wed as snow showers begin to move off the mountains across the Valley. Snow showers will become more widespread 17z-23z, with brief periods of IFR cigs and vis likely under heavier precip. Could see some areas of low visibility in blowing dust as well, especially nr portion of the Valley in the afternoon. South winds overnight will shift to the sw and become strong after 15z Wed, with some gusts approaching 50 kts after 20z. At KCOS, VFR tonight, then MVFR cigs with a chance of snow showers after 15z Wed as a cold front drops through the area. Expect a period of gusty sw winds until 02z, then lighter e-ne winds overnight and Wed morning. Winds will likely become s-sw after 22z on Wed as snow showers move through and front lifts back north through the terminal. At KPUB, VFR the next 24 hrs. Gusty west winds expected this afternoon and evening, then a lighter w-sw wind overnight. E-NE winds then forecast after 11z Wed morning behind a cold front, with lowering VFR cigs. Low chance of rain/snow showers Wed after 18z, then strong sw winds develop after 21z, with gusts to 40 kts possible as front lifts back north. && .PUB WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 5 AM MST Thursday for COZ058-059- 061>063-072>075. Winter Storm Warning until 5 AM MST Thursday for COZ060-066. Blizzard Warning until 5 AM MST Thursday for COZ067-068. High Wind Warning from noon to 7 PM MST Wednesday for COZ069>075- 078>080-087-088-094-099. Winter Weather Advisory from 8 AM to 8 PM MST Wednesday for COZ070-071. Winter Weather Advisory from 11 AM to 8 PM MST Wednesday for COZ084. && $$ UPDATE...RODRIGUEZ SHORT TERM...PETERSEN LONG TERM...SIMCOE AVIATION...PETERSEN