Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/21/22

Area Forecast Discussion
National Weather Service Lincoln IL
727 PM CST Thu Jan 20 2022 .SYNOPSIS... Issued at 239 PM CST Thu Jan 20 2022 Colder weather will persist through the end of the week as strong Canadian high pressure remains settled over the Midwest. Overnight lows will be below zero northwest of the Illinois river to the lower teens in the southeast. Temperatures will remain below normal through the weekend. A few chances for light snow look possible Sunday and once again early next week. && .UPDATE... Issued at 727 PM CST Thu Jan 20 2022 Expansive stratocumulus deck across Indiana continues to edge westward toward I-57 this evening, but has been having some difficulty there. 925-850 mb humidity plots off the RAP model do not show much potential for getting any further west, as the high pressure center pushes into western Illinois, and humidity levels at that layer drop after midnight. Forecast has been updated to hit the clouds harder along and east of I-57, mainly this evening and just past midnight. Elsewhere, clear skies expected overnight, and the forecast is generally on track. && .SHORT TERM...(Tonight through Friday) ISSUED AT 239 PM CST Thu Jan 20 2022 High pressure centered over western IA will continue to dominate the weather across the CWA through tonight. As the high shifts slowly east, winds will become lighter tonight. Even though overnight lows will range from below zero northwest of the IL river to the lower teens in the southeast, wind chills will not be as cold as they were this morning. Wind chills will range from around zero in the southeast to -5 to -10 northwest of I-55. Daytime highs tomorrow will be warmer, but still below normal/below freezing. && .LONG TERM...(Friday night through Thursday) ISSUED AT 239 PM CST Thu Jan 20 2022 The northwest flow pattern we are in will continue through the weekend and next week. This pattern will keep us from getting bitter cold, but a couple of chances of light snow will be possible, once this weekend and the other the beginning of next week. The weekend chance will be late Sat night through Sun morning with most precip along and north of I-74. Some accumulation is possible, but only around 1/2 to 1 inch. The other chance will be Mon through Tue morning. The models differ enough that only a slight chance of precip is forecasted at the moment. The GFS appears to be the most aggressive, while the ECMWF and Canadian have less qpf. Current temp forecast through this period suggests p-type will be rain and snow. Temp forecast through the extended will remain below normal, except for upper 30s to mid 40s for Monday. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) ISSUED AT 510 PM CST Thu Jan 20 2022 VFR conditions expected the next 24 hours. Main cloud source remains with the expansive cloud field over Indiana, which has oozed west to near KCMI/KMTO. However, heights around 4000 feet will prevail with these clouds, and they should diminish in eastern Illinois after 06Z. North winds this evening will shift clockwise and mainly be out of the south by 18Z Friday. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Geelhart SYNOPSIS...Auten SHORT TERM...Auten LONG TERM...Auten AVIATION...Geelhart
Area Forecast Discussion
National Weather Service Melbourne FL
815 PM EST Thu Jan 20 2022 .UPDATE... Current...Weak surface ridge over Florida has pretty much collapsed ahead of the approaching cold front, which extends from the eastern panhandle into SE GA. Local radar imagery over central/SE FL shows convection which began to proliferate near/south of Lake Okeechobee has spread rapidly NE across areas from near Fort Drum-Fort Pierce southward. NLDN/ENTLN data has yet to show any lightning activity within the more intense cells. This mini-burst of convection seems to have been well-forecast by late afternoon runs of the HRRR. Remainder of tonight...The 23Z HRRR run lifts the ongoing activity rapidly NE out over the Atlantic with any overnight redevelopment weaker and a little farther east. Some guidance is also showing more in the way of late night fog development across the souther third to half of the CWA, emanating from more widespread coverage over SW FL. The evening update will trend toward the mesoscale guidance with both fog and convection. Win the small chance for evening lightning storms over land, but keep them over the Atlantic given the greater nocturnal instability over the southern Gulf Stream. Will also add patches/areas of late night (09Z-12Z) fog for the SE 4 counties, focusing greatest areal coverage across Okeechobee County. Any other changes to the grids/ZFP will be cosmetic. && .AVIATION...00Z TAF package added TEMPO groups for VSBY/CIGS to cover ongoing precip over the VRB-SUA corridor. For now, have held off on introducing any VSBY reductions in fog 09Z-13Z, however the overnight shift can monitor trends in METARs/RGBNTM imagery and can add some if needed. Later on in the TAF period, VCSH was maintained across the northern aerodromes as the front slowly approaches from the north, starting 14-15Z at LEE-DAB and slowly reaching MCO-TIX, but no farther south than that through 00Z. Have also introduced prevailing -SHRA for LEE-SFB-DAB during the 21Z-23Z time frame and lowered prevailing CIGs to BKN018-025 per mesomodel guidance. && .MARINE... Overnight...Prevailing offshore/SW flow AOB 10KT gradually shifts to W and then NW for the Volusia/north Brevard waters. Per late evening buoy obs, have capped seas at 2 feet tonight and through most of Friday, given the slowing approach of the cold front from the north. && Cristaldi/Sedlock && .PREV DISCUSSION... (Issued 359 PM EST Thu Jan 20 2022) Friday...A cold front will approach Florida as a mid-upper level trough dips down into the Southeast. There still remains a little uncertainty in the evolution of this system. CAPE and shear are lacking across most of east central Florida, and a slot of dry air wedge ahead of the front will hinder precip development through the day, so the most likely areas for lightning storms will be south of Osceola county. Isolated to scattered showers, and a lightning storm or two, will continue to be possible through the Treasure Coast and Okeechobee counties. An isolated strong to severe thunderstorm will be possible in Martin county. Rain chances will increase for Volusia and Lake counties in the morning, 20-30 percent, as the cold front creeps its way south. Rain chances increase up to 20 percent in Orange and Seminole counties later in the evening. Afternoon highs will be in the low to mid 70s as northerly winds and increasing cloud cover hamper daytime heating. Saturday... The cold front located south of the area, is expected to clear the Florida peninsula by early morning. Locally, northerly surface winds around 10 mph expected inland and 10-15 mph along the coast with higher gusts possible. Strengthening southwest 700mb winds will pull moisture from down south into east central Florida, causing light to moderate stratiform rain to be expected for much of the day on Saturday. This additional moisture will be aided by an inverted trough that is expected to set up off the eastern Florida coast Saturday morning, coupled with a vorticity maxima across northern Florida that is expected to continue to push southward through the Florida peninsula through the day, causing a rainy day to be expected for Saturday. Highest rain chances will occur in the afternoon, with 40 percent areawide, except 50 percent along the immediate coast of the Treasure Coast. Rain chances begin to lessen in the evening as the vorticity maxima exits the area, lowering PoP chances to 20-30 percent inland, and 40 percent along the coast. Cooler afternoon temperatures are expected as cloudy skies persist through the time period, coupled with the light to moderate rain for much of the day. Afternoon temperatures will be in the upper 50s to low 60s along and north of I-4, and upper 60s to low 70s elsewhere. Overnight lows will be in the upper 30s to low 40s across the far north, mid to upper 40s elsewhere, except low to mid 50s across the Treasure Coast and Okeechobee county. Sunday... A high pressure over Texas will build eastward and push across the Florida peninsula through the day on Sunday. Locally, skies will begin to clear by Sunday morning as drier air filters into east central Florida. Rain chances will continue to decrease on Sunday, with mostly dry conditions expected after sunrise and continue through the day. A slight chance of showers will remain along the immediate coast to Martin county however, with the majority of rain chances occurring across the Atlantic waters. Afternoon highs will be in the low 60s across the north, and mid to upper 60s across the south. Overnight lows will be cooler, with lows in the mid to upper 30s across the north and across the interior, and low 40s along the immediate coast and the Treasure coast. Monday-Wednesday... Upper level trough over the Great Lakes on Monday morning will push eastward through the day. A cold front across the Midwest extending into Texas on Tuesday will begin to slowly move eastward, reaching the Florida panhandle by Tuesday afternoon. The cold front will then push through east central Florida Wednesday, clearing the local area by the afternoon. Locally, rain chances will increase through Tuesday as the cold front approaches the Florida peninsula and begin to tapper off on Wednesday as the cold front moves through. Mostly dry conditions expected Monday, with a slight chance of showers across the north Monday night and into Tuesday. Highest rain chances (PoP 50) will occur area wide on Tuesday afternoon, with rain chances tapering off to 30 percent area wide on Tuesday night. Rain chances will continue to decrease Wednesday afternoon, with 20 percent from Seminole county southward, except 30 percent across the Martin county coast. Afternoon highs on Monday will be in the low to mid 60s areawide, except upper 60s across the Treasure Coast and Okeechobee counties. Tuesday and Wednesday, highs will be a little warmer, with mid 60s across the far north, and upper 60s to low 70s everywhere else. Overnight lows on Monday will be in the mid to upper 40s areawide, except for low to mid 50s across the Treasure Coast; Tuesday will have upper 40s to low 50s across the north and over the interior, with mid 50s across the Treasure Coast. && .MARINE... Friday...Generally favorable boating conditions. The ridge axis from high pressure in the northwest Atlantic is barely reaching local waters, and will drift southward. Southerly winds 5-10 knots will veer to northerly and increase to 10 to 15 in the northern waters, while the southern waters become light and variable, through Friday afternoon. Isolated to scattered showers, and a thunderstorm or two, will be possible in the Treasure Coast waters and the Brevard offshore waters through the period. Isolated to scattered showers will be possible in the Volusia waters Friday afternoon. Boating conditions will begin to deteriorate Friday night as seas build to 6-9 ft across the northern waters. Saturday-Wednesday... Boating conditions will continue to deteriorate Saturday as the cold front clears the Florida peninsula by early Saturday morning. Seas will be to 4-7 ft in the nearshore waters, and 7-10 ft in the offshore waters Saturday. Seas will begin to slowly decrease Sunday, lowering to 6-9 ft by Sunday night, 4-6 ft by Monday morning, and 3-4 ft by Tuesday. Seas will slowly build to 3-6ft by Wednesday afternoon. North to northeast winds 15-20 KT Saturday will continue through Sunday, before slowly decreasing to 10-15 KT Sunday nigh. Winds will then veer southeast Monday and northwest by Wednesday. A persistent light to moderate stratiform rain is expected for much of the day on Saturday, before being confined to the Treasure coast and offshore Brevard waters by Sunday. Rain chances enter the forecast once again for all the east central Florida waters Tuesday and Wednesday. && .PRELIMINARY POINT TEMPS/POPS... DAB 57 72 53 63 / 0 20 40 40 MCO 57 77 57 65 / 0 10 20 40 MLB 56 76 59 70 / 10 10 30 40 VRB 57 78 61 72 / 20 20 30 40 LEE 56 73 49 59 / 0 30 30 40 SFB 56 75 54 63 / 0 20 30 40 ORL 58 76 57 64 / 0 10 20 40 FPR 57 77 60 73 / 30 30 40 50 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. && $$
Area Forecast Discussion...UPDATED
National Weather Service Mobile AL
555 PM CST Thu Jan 20 2022 .AVIATION... 00Z issuance...A complex near term aviation forecast presents itself as IFR to MVFR ceilings have settled into the area, with isolated locations reporting LIFR ceilings. Strong northerly surface winds will continue to bring sustained winds of 10 to 15 knots gusting to 20 to 25 knots through Friday. The tricky part of the forecast is overnight tonight into Friday morning as the current dry conditions transition to the potential for light freezing rain after 08z tonight through 18z Friday. Best chances for this is across the western FL panhandle, far southeastern MS, and far southwestern AL where a winter weather advisory is in effect. Anticipating no more than a glaze of freezing rain accumulations at this time. Light rain may continue southeast of the I-65 corridor into late Friday morning before dry conditions settle back into the area for Friday afternoon. Upper-end MVFR to VFR ceilings should return area-wide by late tonight as ceilings lift. /22 && .PREV DISCUSSION... /issued 359 PM CST Thu Jan 20 2022/ NEAR TERM UPDATE /Now Through Friday/...A very complex forecast is on tap through Friday. I will give a quick synopsis here and detail the expected evolution of freezing rain through Friday morning below. Overall we have had a strong arctic cold front push across the area this morning, and strong northerly surface winds have enveloped the area. Temperatures have crashed in the wake of the front, already dropping into the lower to middle 40`s in most locations. Expect temperatures to continue to fall into the middle to upper 30`s by this evening for most locations. A pair of mid to upper level shortwaves located over the central and south- central U.S. will move eastward through the near term period. The southern stream shortwave will be responsible for potential impactful weather during the overnight hours tonight into Friday morning bringing a chance for freezing rain to southeastern MS and southwestern AL into western FL panhandle. Details on this are explained in greater detail below. Once this system moves through, we should dry out for the better part of Friday late morning into the evening. For the rest of this evening, temperatures fall into the middle to upper 30`s by this evening and continue crashing into the middle to upper 20`s tonight northwest of the I-65 corridor and upper 20`s and lower 30`s elsewhere. Rain continues to taper off in the wake of the arctic front by this evening as cold, dry air continues to work its way in at the surface across the area. This brings us to the possible light freezing rain event for portions of southeastern MS, southwestern AL, and the western FL panhandle. A light glaze of freezing rain is possible overnight tonight into Friday morning across portions of southwestern AL, southeastern MS, and the western FL panhandle... An arctic front will have stalled south of the coastline while warm advection continues to override the cold dome rooted over the region and another shortwave approaches the area from the west. This will set the stage for overrunning of precipitation across portions of the area, particularly locations nearer the coast where a winter weather advisory has been issued. Synoptically, the stage is set for overrunning, and forecast soundings from various hi-res CAMs and some global models indicates a less prevalent 800 to 700mb dry layer than previously advertised, likely owing to some slightly stronger dynamics with subtle trends in the overall modest amplification of the system. A layer of above freezing temperatures between the 900 and 700mb layer will allow for snow falling into this layer to become all liquid precipitation which then proceeds to fall into the subfreezing surface layer, resulting in high confidence on any falling precipitation to be in the form of freezing rain. A zone of modest 850 to 700mb frontogenesis should develop over the advisory area during the overnight into early morning hours Friday in response to the incoming dynamics. As a result of the above, forecast guidance has trended northwest with light precipitation and slightly increased probabilities of freezing rain over the area. It is possible that model guidance is under- representing the extent of precipitation coverage and is delayed in onset of precipitation which is a common bias in overrunning events. It appears the trend in guidance over the past 12 hours has been catching on to this somewhat, along with the adjustments in the synoptics. It is going to be critical to watch surface observations over the next 12 hours and compare them to how they are verifying with respect to the various hi-res CAMs. Currently the 3KM NAM has been verifying best with its depiction of surface dewpoints and temperatures, and it is one of the drier low level solutions on the table. Now you may be thinking that drier low levels would reduce freezing rain potential, and although it would eat into some of the overall precipitation, it will allow for a colder wetbulb temperature in the upper 20`s versus lower 30`s. This is extremely important in allowing for surface temperatures to support efficient freezing of any rainfall that reaches the surface. With all this said, I also have to acknowledge the potential that there isn`t much if any precipitation at all during the overnight. This scenario is still on the table and would occur if for some reason temperatures and dewpoints fail to adequately cool at the surface (like the HRRR from its 12z run this morning) or if that dry layer in the 800 to 700mb level manages to be more potent than forecast. For now, it appears there is a subtle trend toward a wetter solution overnight tonight into Friday morning across the advisory area, and trends in guidance and observations will have to be monitored as we move forward the next 12 to 24 hours. Beyond this, expect a cold day Friday highs in the upper 30`s to lower 40`s for most locations and dry weather to return by late morning into early afternoon. Any precipitation ongoing by this point should be all liquid. MM/25 SHORT TERM /Friday night Through Sunday night/...Some lingering precipitation down near the coast Friday night, but this will be moving south and should be to the south of the forecast area ahead of the late night min temps. Lows near the coast where any precip could be lingering are expected to be in the low to mid 30s, and if temps drop just a tad lower we could see a very slight potential for very minor additional freezing rain, but this is not expected at this time. Over inland areas where temps will be well below freezing on Friday night, no precip is expected. The most probable outcome for Friday night is that any light rainfall lingering over our coastal zones will end prior to temperatures dropping to freezing or below. Low temperatures will range from the lower 20s across interior southeast Mississippi and southwest Alabama, to the upper 20s/lower 30s along the I-10 corridor, and middle to upper 30s along the immediate coast. A return to dry and cold weather is expected on Saturday with clouds gradually clearing from west to east through the day. The dry and cold weather will then continue through the remainder of the short term period as surface high pressure moves east across the region. Temperatures on Saturday will range from the middle 40s over interior areas to lower 50s along the coast. Brisk northeast winds will make conditions feel colder. Lows Saturday night back down into the low to mid 20s over interior zones, upper 20s to lower 30s at the coast. Temps slightly warmer on Sunday and Sunday night, with highs on Sunday being mainly in the low to mid 50s and lows Sunday night in the mid and upper 20s inland and mid to upper 30s near the coast. A hard freeze will be possible over interior sections with freezing temperatures expected all the way to the coast. Right now it appears that min temps will be just above our criteria for hard freeze (20 degrees or colder). /12 EXTENDED TERM /Monday Through Thursday/...Did not make a lot of changes to extended period. Looks mainly dry through most of the period, with the next chance for precip coming Monday night through Tuesday. The area dries back out on Wednesday. High temperatures will remain on the cooler-side through the middle part of next week in this pattern, mainly in the 50s each day. Low temps moderate somewhat Monday and Tuesday night, with lows Low temperatures tank into the 20s inland with low 30s at the coast Sunday night into Monday morning with lows mainly in the 30s, but drop significantly once again by Wednesday night in the wake of the system, with lows in the mid and upper 20s inland and low to mid 30s at the coast. /12 MARINE...A cold front moving across the marine area this morning will push south of the coastal waters by this afternoon. A moderate to strong offshore flow is developing in the wake of the front, and will persist through Friday night or early Saturday. A Small Craft Advisory is in effect for most of the marine area through late Friday night. Northerly winds become moderate Saturday night and Sunday before turning more east to southeasterly by Monday ahead of the next approaching system. /12 && .MOB WATCHES/WARNINGS/ADVISORIES... AL...Winter Weather Advisory from midnight tonight to noon CST Friday for ALZ261>266. FL...High Rip Current Risk until 6 PM CST this evening for FLZ202-204- 206. Winter Weather Advisory from midnight tonight to noon CST Friday for FLZ201-202. MS...Winter Weather Advisory from midnight tonight to noon CST Friday for MSZ078-079. GM...Small Craft Advisory until noon CST Saturday for GMZ650-655-670- 675. Small Craft Advisory until 6 AM CST Saturday for GMZ630>632. && $$ This product is also available on the web at:
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
552 PM CST Thu Jan 20 2022 .DISCUSSION...(This evening through Thursday) Issued at 302 PM CST Thu Jan 20 2022 Key Messages - Wind chills will once again fall 25 below to 30 below through tomorrow morning. - Multiple clippers are expected Friday through Monday, resulting in several inches of snow when all is said and done. With high pressure centered overhead, winds have become calm allowing for a brief break from bitterly cold wind chills. It`s still plenty cold with most locations struggling to make it above zero. Another very cold night is on tap as winds begin to strengthen again on the backside of the high as it continues to move off to the southeast. Another Wind Chill Advisory is in place area wide through tomorrow morning. Temperatures tomorrow will manage to get into the teens and 20s thanks to warm air filtering in from the south ahead of our first of three clippers. Did raise temps a bit out in far western Minnesota into the upper 20s. However, gusty winds will ramp up into the late morning hours, so wind chills will again make it feel like it`s in the single digits below zero for the eastern half of the CWA with readings of 5 to 10 above out west. Winds look especially feisty along the Buffalo Ridge, so have introduced a Wind Advisory for our far western counties in coordination with neighboring offices. Light snow will move in during the evening and overnight hours with totals of around a half inch to an inch. Highest amounts are expected across central Minnesota and western Wisconsin. Winds will gradually turn from south to northwest overnight with the passage of this system. Some stronger gusts may linger into the overnight hours, so some patchy blowing snow is possible, particularly across western Minnesota. Moving into the weekend, we`ll be dry during the day Saturday before another clipper approaches by late afternoon. This one looks to set up a little further to the south and has a deep DGZ, so another inch or two is possible by Sunday morning. Our third and final weekend clipper is still on track to be the potentially strongest of the set. A slight uptick in moisture looks to aid in the QPF amounts, which will likely allow for a swath of a few inches of snow to fall across the area. Snow develops from northwest to southeast by Sunday evening and continues into early Monday. Another arctic airmass moves in by Monday night and lasts into midweek. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 543 PM CST Thu Jan 20 2022 We will see strengthening south winds tonight through Friday morning, with a band of snow moving across western MN during the afternoon. Have gone with a timing that`s a little slower than the HRRR (which is on the fast end of the model spread), but 24 hours out, there`s pretty good agreement on the timing of this band of snow that only looks to last 2-4 hours. KMSP...Snow looks to start at MSP between 0z and 2z and only last 3 or 4 hours, with a quick inch of snow expected out of it. /OUTLOOK FOR KMSP/ Sat...Chc MVFR cigs. -SN/IFR overnight. Wind NW 10-15 kts. Sun...VFR. -SN/IFR overnight. Wind N bcmg S 5-10 kts. Mon...Chc -SN/IFR in mrng. Bcmg VFR. Wind N 10-15 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...Wind Chill Advisory from 9 PM this evening to 10 AM CST Friday for Anoka-Benton-Blue Earth-Brown-Carver-Chisago-Dakota-Faribault- Freeborn-Goodhue-Hennepin-Isanti-Kanabec-Le Sueur-Martin- McLeod-Mille Lacs-Nicollet-Ramsey-Rice-Scott-Sherburne-Sibley- Steele-Waseca-Washington-Watonwan-Wright. Wind Chill Advisory until 9 AM CST Friday for Chippewa-Douglas- Kandiyohi-Lac Qui Parle-Meeker-Morrison-Pope-Redwood-Renville- Stearns-Stevens-Swift-Todd-Yellow Medicine. Wind Advisory from 9 AM to 3 PM CST Friday for Lac Qui Parle- Redwood-Yellow Medicine. WI...Wind Chill Advisory from 9 PM this evening to 10 AM CST Friday for Barron-Chippewa-Dunn-Eau Claire-Pepin-Pierce-Polk-Rusk-St. Croix. && $$ DISCUSSION...Dye AVIATION...MPG