Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/07/24


Area Forecast Discussion
National Weather Service Corpus Christi TX
500 PM CST Wed Mar 6 2024 ...New AVIATION... .SHORT TERM... (Tonight through Thursday night) Issued at 338 PM CST Wed Mar 6 2024 Key Message -Fog/low clouds return both marine and land this evening. The main concern will be the low cloud/fog issues as we get into one more night with sea fog over the Coastal Bend. Fog and low clouds are beginning to move shore near Matagorda bay, but it doesn`t last long as the fog mixes out over land. The low clouds look like they stall up there for a few hours, before moving south along the coast. Forecast soundings show that the stratus starts in the early evening, then builds down to the sfc, with the sfc fog in and out for a while until around 09z/Thu, and then stays and moves inland. There is a concern that the somewhat higher winds tonight will be enough to keep it as stratus, not letting it build down. Model soundings lean more toward fog, although the HRRR leaves some room for patchy fog and stratus. Consensus short model and GLAMP data show more of a up and down with the visibilities. So will leave the current patchy fog and allow the evening shift to monitor trends. Thursday, the fog will lift by mid morning again, if not sooner, but it will remain hazy over the region. Winds will remain onshore all day, which will help the Gulf water temperatures warm, limiting the fog chances going into Thursday night. A pre-frontal trough moves through the region overnight, but the real support (500 mb jet streak) trails the trough, and is focusing the precipitation to the north in the Hill Country. Winds will remain onshore in the Coastal Bend, but will diminish as trough moves into the Brush Country, allowing for some fog formation again early Friday morning. && .LONG TERM... (Friday through next Tuesday) Issued at 338 PM CST Wed Mar 6 2024 Key Messages: -Isolated to Scattered Showers and Thunderstorms in the Victoria Crossroads and Coastal Bend -Elevated Fire Weather Conditions possible over the Brush Country and Rio Grande Plains Friday and Saturday The forecast has be remaining pretty steady for the long period. As the we progress during the day Friday, a prefrontal surface trough will develop ahead of the cold front that will push through later in the day. With above normal moisture ahead of the trough (1.6-1.8 inches), sufficient CAPE values (900-1200 J/kg), and a relatively uncapped environment around the Coastal Bend and Victoria Crossroads showers and thunderstorms are possible (20-40%) Friday morning through midday. This prompted SPC to clip a portion of the Victoria Crossroads in a Marginal for severe weather which coincides with the higher CAPE values. The front should push offshore by 20-23Z, with a reinforcing surge coming behind it later on that night. Out west with the front arriving earlier, the potential for fire weather conditions exist during the day Friday in the Rio Grande Plains and Brush Country. Conditions will taper off during the evening before ramping up again over the same areas Saturday. Minimum RH values will drop below 20% Friday and will be around 20% Saturday. Temperatures behind the front will be more spring like with highs in the 70s. Warmer conditions return by the middle of next week with highs returning to the 90s. && .AVIATION... (00Z TAFS) Issued at 449 PM CST Wed Mar 6 2024 VFR conditions will persist for the next several hours over South Texas. MVFR ceilings will develop around 03Z for those over the Coastal Plains and points east. MVFR to IFR visibility is possible as dawn approaches, mainly along the coast. VFR conditions will return to the area by midday Thursday. && .MARINE... Issued at 338 PM CST Wed Mar 6 2024 Weak onshore flow will become weak to moderate tonight, then persist through Thursday. Areas of fog may occur over the bays and nearshore waters, as well, Thursday night/Friday morning before the cold front moves through the region. The combination of an upper level disturbance and a prefrontal trough of low pressure may contribute to isolated to scattered showers and isolated thunderstorms Friday. A cold front will move across the waters Friday night and Saturday morning. In response to the front, strong to very strong offshore flow is expected over the coastal waters Saturday through early Sunday creating Small Craft Advisory conditions. Winds will transition to weak to moderate northeast by Sunday night, as the surface pressure gradient relaxes before becoming weak by Monday. && .PRELIMINARY POINT TEMPS/POPS... Corpus Christi 66 78 69 85 / 0 10 0 20 Victoria 64 78 67 83 / 0 10 10 40 Laredo 71 90 69 87 / 0 10 10 10 Alice 66 82 68 87 / 0 10 0 20 Rockport 64 75 66 83 / 0 10 0 20 Cotulla 68 85 67 87 / 0 10 10 10 Kingsville 66 80 69 84 / 0 10 0 10 Navy Corpus 66 74 67 81 / 0 10 0 20 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ SHORT TERM...JSL LONG TERM....NP AVIATION...LS/77
Area Forecast Discussion
National Weather Service Hastings NE
541 PM CST Wed Mar 6 2024 .KEY MESSAGES... - Chances for rain (20-40%) increase from south to north throughout the day on Thursday, with chances (40-80%) becoming widespread Thursday afternoon. - Most areas will see light rain, with uncertainty remaining on how widespread the higher totals are. - A band of light snow (0.1-1") will move through the area overnight Thursday into Friday morning. The highest chances to see an inch of snow are northwest of the Tri-Cities - Above normal temperatures return this weekend and continue next week with highs in the 50s and 60s. && .DISCUSSION... Issued at 421 PM CST Wed Mar 6 2024 This afternoon through overnight... Breezy southerly winds with gusts of 25-30mph will decrease this evening. Lows tonight will be in the low (north) to upper 30s (south). A cold front will move through the area overnight, with winds becoming northerly by sunrise. Chances for rain (20-50%) enter southern portions of the area before sunrise on Thursday. Thursday... Chances for rain (30-80%) increase from south to north across the area during the day on Thursday, with a 50-80% chance across the area by the afternoon. A few non-severe thunderstorms are possible across portions of north central Kansas during the afternoon and evening hours on Thursday. The ECMWF and it`s ensembles place the highest chances (40-60%) for 0.5 inches or more of rain across portions of north central Kansas. The GFS and it`s ensembles have precipitation more widespread, but have lower chances to see half an inch or more (20-40% across the area). Higher resolution guidance continues this uncertainty, with the NAM placing a band of heavier rainfall across portions of north central Kansas, and the HRRR having lighter but more widespread precipitation. Regardless of the exact amounts, most areas will see light rain. Thursday Evening through Friday... Rain will transition to snow along the backside of the system as it progresses east overnight Thursday. Areas northwest of the Tri- Cities may see a transition to snow during the late evening hours on Thursday. The band of snow along the backside of the system will move southeast across the area during the morning hours on Friday, exiting southeastern portions of the area during the early afternoon hours on Friday. Accumulations are expected to remain light, with most areas remaining under half an inch. The highest chances to see an inch of accumulation are northwest of the Tri-Cities where snow will occur longer. Temperatures will be cooler on Friday, with highs in the upper 30s to low 40s. Winds will be gusty throughout the day on Friday, with winds decreasing overnight. Saturday through Wednesday... Any lingering snow will quickly melt this weekend as an upper level ridge builds over the area. Highs on Saturday will be in the upper 40s to low 50s, climbing to the 60s on Sunday, and into the upper 60s to start next week. Warm temperatures along with breezy winds will lead to the return of fire weather next week. Currently relative humidity values are forecast to remain above fire weather criteria (RH < 20%), but if relative humidity values become lower than what is currently expected, fire weather concerns would increase. The next chance for rain (15-20%) arrives Wednesday with an approaching trough. && .AVIATION /00Z TAFS THROUGH 00Z FRIDAY/... Issued at 536 PM CST Wed Mar 6 2024 VFR conditions are expected at both terminals this evening and into the overnight hours. Southeasterly to south-southeasterly winds will decrease this evening, becoming light and variable overnight. An advancing cold front tonight will shift winds to the north-northwest around sunrise, with winds increasing behind the front. Additionally, with the arrival of the front, expect ceilings to lower to MVFR levels. After sunrise, a few showers will be possible through the morning, with rain chances (40-70%) increasing by mid to late morning and continuing through the end of the forecast period. && .GID WATCHES/WARNINGS/ADVISORIES... NE...None. KS...None. && $$ DISCUSSION...Davis AVIATION...Wekesser
Area Forecast Discussion
National Weather Service Green Bay WI
522 PM CST Wed Mar 6 2024 Updated aviation portion for 00Z TAF issuance .KEY MESSAGES... - Chances for a rain/snow mix arrive Friday morning, although when and where the transition from rain to snow will occur is still uncertain. Highest snowfall amounts of 1 to 2 inches likely to be confined to east-central Wisconsin. - Rest of the forecast period looks to be mild and dry with temperatures running around 8 to 12 degrees above average. && .DISCUSSION... Issued at 206 PM CST Wed Mar 6 2024 Short Term...Tonight and Thursday The latest RAP analysis and satellite/radar imagery show high pressure centered over northern Ontario and James Bay. Northeast or east winds emanating out of the high continue to feed in very dry air below 10 kft across the region. Satellite estimates place precipitable water values around 25% of normal over far northern WI early this afternoon. Looking upstream, a storm system is moving northeast across the northern Plains, spreading widespread overcast conditions into the northern Mississippi Valley. Precipitation mainly exists to the north and northwest of the surface low positioned over northern South Dakota as southeast winds feed dry air into the system. Forecast concerns mainly revolve around low precip chances and low humidities. Sky and Precip Chances: Low pressure will reorganize as it tracks northeast from the northern Plains and into Manitoba and Ontario on Thursday. As a result of this track, strong forcing will remain well northwest of the region. Wisconsin will be positioned between this dynamic forcing and gulf moisture spreading into the Kansas-Missouri area, so no precip is expected even with the cold front approaching northwest WI by late Thursday afternoon. However, mid-clouds will spread across the region tonight and hang around for part of the day on Thursday. Models also indicate low stratus will get recycled to the northwest from southern Lower Michigan and into east-central WI on Thursday afternoon. This moist low level flow could also lead to an increase of cloud cover on Thursday. Temps: Low level temperatures will continue to slowly warm through Thursday afternoon. Clouds will partially offset this warming trend, so look for highs similar to today`s readings on Thursday afternoon. Low temps will be warmer tonight due to more boundary layer wind and cloud cover. Low Humidities: Low level moisture will increase as the flow turns to the southeast on Thursday. After minimum humidities between 20-25% this afternoon, minimum humidities should increase to 30-35% on Thursday afternoon. Low wind speeds and high fuel moisture should continue minimize fire weather concerns even with the low humidities. Long Term...Thursday Night Through Wednesday Main focus for the extended will be a tale of two surface lows bringing rain/snow chances to the forecast area Friday morning. The first surface low and trailing cold front are progged to move across the northern Plains before clipping the Minnesota arrowhead Thursday afternoon and ejecting north into Ontario. Meanwhile, another surface low will trek from the southern Plains up into the Midwest, bringing more widespread precip chances to the western Great Lakes. As the system departs to the northeast over the weekend, upper-level ridging will then keep most of the Midwest mild and dry. Friday and Saturday precip chances... Precip chances enter the forecast area Friday morning as a shortwave drops south into Wisconsin and confluent flow sets up across the Great Lakes. During this time, a warm front is expected to lift north across Illinois while a concurrent cold front sweeps east across Wisconsin. Precip type will be a hindrance to the forecast as there are several sources of uncertainty regarding boundary layer temperatures and moisture content throughout the column. Light warm air advection rain will likely spread north across central and eastern Wisconsin Friday morning, although the strongest signal for isentropic ascent ahead of the warm front remains to our south. Strongest forcing then arrives later Friday morning as a cold front moves east across the upper Midwest. Models are picking up on a moderate mid-level FGEN band associated with the cold front, suggesting that periods of locally heavy precipitation may be possible. However, pinpointing the transition from rain to snow will be tricky. Any precip that falls early Friday morning will have to contend with mid-level dry air before the column saturates, suggesting that seeder feeder processes may be dominant during this time. Thus, chances for patchy drizzle/freezing drizzle would not be out of the question. Opted to leave freezing rain out of the forecast. A near isothermal layer hovering right around 0 degrees C up to ~850 mb introduces additional uncertainty as well. Precip will likely transition to mostly snow Friday evening as post-frontal temperatures fall to the low 20s to low 30s across the area. Highest snowfall amounts of 1 to 2 inches will mainly be confined to east-central Wisconsin where strongest FGEN sets up. Light snow may continue into Saturday morning as cyclonic flow and cold air advection linger on the back end of the exiting system. Rest of the extended... Following the weekend`s system, upper- level ridging will build into the Great Lakes region to keep the prevailing weather mild and dry through the extended. Predominantly south/southwesterly winds will advect warmer air up into the region, resulting in temperatures running around 8 to 12 degrees above average for this time of year. Next chances for precip arrive toward the end of the forecast period, although details are sparse this far out. && .AVIATION...for 00Z TAF Issuance Issued at 522 PM CST Wed Mar 6 2024 VFR conditions and dry weather will continue through Thursday afternoon as high pressure begins to exit the region. Clouds will increase tonight from west to east but should generally remain about 9-12 kft. A lower cloud deck is forecast to spread into east-central WI from the south and east Thursday afternoon and drop cigs to MVFR conditions by 00Z Friday as moisture from an approaching system moves into far southwest WI. There will be a period of LLWS through the night over northern WI and late tonight over central WI as winds at 2K ft reach 30-35 knots. && .GRB WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION.....MPC/Goodin AVIATION.......Kallas
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1012 PM EST Wed Mar 6 2024 .SYNOPSIS... Above normal temperatures and an active weather pattern will persist through the weekend. A frontal system moves off the Carolina coast tonight taking the rain with it. Dry high pressure briefly controls our weather late tonight and Thursday. A more robust low pressure tracks across the Southeastern States from Friday into the weekend bringing more heavy rain and possible storms. && .NEAR TERM /THROUGH THURSDAY/... Evening Update...An upper trof axis is swinging across the FA currently and the attendant sfc low is still supplying light wrap around precip across the nrn zones. Expect this rain to continue to weaken and dissipate over the next few hours. Moisture at h85 is beginning to lower across the wrn zones while downslope drying is occurring across the Upstate and adj fhills zones. This is making for a tricky fog forecast as any areas that experience increased rad cooling will be suspect for dense fog formation overnight as sfc tdd/s are quite high due to recent precip and winds will remain on the low end. Blended the HRRR and the LAMP visibility guidance as these models are picking up on the latest trends previously not well handled by the op models. The Lakelands, including KAND, shud have a decent shot of dense fog formation and possibly the Upstate thru daybreak. The I-77 corridor, including KCLT, may hold on to enuf low clouds for much of a dense fog issue. As of 200 PM...Low temps will remain above normal with lows mainly in the 40s to lower 50s. Thursday looks like a pleasant day, as mild sfc high pressure crosses the forecast area. There should be little to hold fog and stratus in, so clouds should scatter out by around midday, leaving partly to mostly sunny skies and continued light wind. Highs will be about 10-12 deg above normal, upper 60s to lower 70s. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... As of 155 PM Wednesday: A shortwave trough will be digging into the Desert Southwest tomorrow night with downstream shortwave ridging extending along the Appalachians. Weak easterly low-level flow will advect an uptick in moisture from the Atlantic across the Carolinas with a resulting increase in cloud cover along with a few upslope showers on the Blue Ridge escarpment. Thickening clouds will preclude much overnight cooling with mild low temperatures in the low to mid 50s. The synoptic pattern begins to amplify on Friday as the upstream trough continues to dig across northern Mexico with a resulting strengthening of the upper ridge extending along the East Coast. While heights will rise across the region, clouds and continued upslope showers in the mountains will limit heating with high temperatures confined to the low to upper 60s. The forecast becomes much more active Friday night into Saturday as the upstream trough ejects out of northern Mexico and into the Lower Mississippi Valley. Lee cyclogenesis is progged to occur across northeast New Mexico with the surface low lifting across the Great Plains and into the Great Lakes region by Saturday morning. A trailing cold front is forecast to extend through the Ohio Valley to western Tennessee with a warm front draped roughly along the I-20 corridor. 12z guidance remains in good agreement in depicting the initiation of deep convection along the warm front across southern Mississippi during the day on Friday. Upscale growth into a convective complex appears likely with time with this activity propagating east overnight along the warm front. Subsequent rain cooled air north of the front in concert with convective cold pools will strengthen the warm frontal boundary and help to lock in the boundary along or just south of the I-20 corridor. Furthermore, positive tilt of the upper trough and a relatively weak surface low will result in increasingly veered flow with upper flow oriented parallel to the warm front, which further suggests limited northward progress of the warm sector. Thus, the overall forecast is for elevated thunderstorms and an associated broad stratiform shield to lift into the area from the southwest overnight Friday into Saturday morning with the primary deep convective updrafts anchored on the warm front along I-20. This activity will translate across the area through much of the day Saturday with precipitation gradually tapering off from west to east through the mid to late afternoon. Given the expected southward placement of the warm front, severe weather is not expected at this time. Should the warm front nose into the lower Piedmont, a severe weather threat cannot be ruled out, however, parameter space appears rather disjointed with better shear profiles lifting away from the area before the arrival of surface-based instability. The main hazard will be for flash flooding concerns given antecedent wet conditions from today`s rain. At least a few hundred J/kg of elevated MUCAPE will be possible north of the warm front with the warm frontal circulation helping to provide additional forcing for heavy rain potential. A plume of deep moisture with 1.5" PWATs moving into the Upstate and Piedmont. If convective rainfall rates materialize, a quick couple inches of rain could result in several instance of flash flooding. The ongoing slight risk for excessive rainfall from WPC is well placed based on current guidance. Otherwise, there are indications that a CAD wedge will become established, especially along and north of the I-40 corridor, which will result in another cold and rainy day with high temperatures struggling to reach the 50 degree mark. Have trended temperatures on the cool side of guidance for this reason. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... As of 246 PM Wednesday: A few showers may linger across the mountains and far eastern Piedmont Saturday evening before all precipitation quickly comes to an end. Thereafter, the cold front is expected to push through the area overnight with a drier and cooler airmass filtering into the area. Cold advection shuts off by Monday with modification of the airmass through early next week fostering a return to 70 degree temperatures by Wednesday. Several mornings will also be conducive for radiational cooling with clear skies and light winds in the dry air. While afternoon RH values may fall to near critical levels for fire danger, wet fuels from recent rains should limit any fire danger. && .AVIATION /03Z THURSDAY THROUGH MONDAY/... At KCLT and elsewhere: A mix of MVFR/IFR across all TAF sites this evening as a sfc low is slowly pushing precip and deep moisture east. Have a general downward trend fcst/d for CIGS at all sites to IFR and/or LIFR before daybreak. Decent confidence is had in limiting VSBY to the IFR range with low-end mixing and high cloud cover, however, thinking KAND and lakelands area will have a shot of clearing possibly leading to dense fog before and thru daybreak. VFR conds return to all sites by mid-morning to noon, while winds remain fairly weak and generally aligned n/ly to nw/ly thru the period. Outlook: Another frontal system moves in late Friday thru Saturday. This will bring rain chances and associated flight restrictions as early as Friday, continuing into Saturday, then improving on Sunday as drier air moves in behind the departing front. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None. && $$ SYNOPSIS...DEO NEAR TERM...ARK/SBK SHORT TERM...TW LONG TERM...TW AVIATION...SBK
Area Forecast Discussion...UPDATED
National Weather Service Memphis TN
926 PM CST Wed Mar 6 2024 ...New UPDATE... .UPDATE... Issued at 926 PM CST Wed Mar 6 2024 Relatively quiet weather prevailed over the Midsouth this evening. GOES IR shows low stratus over parts of west TN and north MS. Aloft, the subtropical branch of the upper level jet was spreading high clouds into the region. GOES west showed these high clouds extended out to the tropical Pacific, south of Hawaii. As mentioned in the Aviation Discussion below, the low stratus may expand overnight, while the high level cirrus/cirrostratus will likely become thicker. With dewpoints in the upper 40s to lower 50s, temperatures should only modestly cool overnight. With light winds, patchy fog can`t be ruled out, mainly over northeast MS. Current forecast is on track. Only minor additions made for patchy fog overnight. PWB && .SYNOPSIS... Issued at 150 PM CST Wed Mar 6 2024 A low pressure system will bring wet and unsettled weather tomorrow and Friday. Expect showers and thunderstorms to increase tomorrow afternoon, becoming more widespread with the occasional strong thunderstorm by Friday afternoon. After the cold front moves through Saturday, dry weather with seasonable temperatures in the 50s and 60s returns through the rest of the weekend into midweek. && .DISCUSSION... (This evening through next Tuesday) Issued at 150 PM CST Wed Mar 6 2024 Post-frontal stratus is still lingering across much of the Mid- South, especially west Tennessee. This will likely keep temperatures in the mid 60s today across west Tennessee while portions of north Mississippi creep into the low 70s under mostly clear skies. Cloud cover is expected to gradually erode tonight as the front pulls farther away, which will support patchy fog development especially along the MS-TN state line. The latest HRRR is highlighting a corridor from Corinth, MS to Oxford, MS with patchy dense fog overnight through sunrise. A low pressure system currently over the southern Plains will very slowly approach the Mid-South tomorrow. As the system approaches, a secondary surface low looks to materialize over the Upper Mississippi River Valley on Friday morning. The trailing cold front from this second system will be the kickstarter for strong to severe thunderstorms Friday afternoon and evening. Global models` ensemble solutions suggest the corridor of favorable instability (30-50% probability of CAPE > 500 J/kg) to be displaced to the southwest over the ArkLaTex and Gulf Coast while the convection moves through the Mid-South. Overall joint probabilities of supportive instability AND shear during the time of convection and FROPA is fairly low. In other words, the kinematics and dynamics of this system may not line up. This is a low confidence, conditional event. If strong to severe storms do develop, damaging winds and large hail would be the primary threats Friday afternoon and evening. Both the initial and reinforcing cold fronts are forecast to clear the area by Saturday afternoon. The airmass behind the front originates from the Pacific and thus will not make a noticeable difference in temperatures post-FROPA. The coolest morning of this forecast package looks to be Sunday morning just after the front passes, aided by both cold air advection and radiational cooling under mostly clear skies and light winds from surface high pressure. NBM probabilities of temperatures below 32 degrees are less than 20% areawide Sunday and Monday mornings, but it will still be chilly and seasonably cool both days. Forecast surface analyses depict a 1024 mb surface high sitting right over north Mississippi by Monday morning. This will create a very pleasant start to the work week with cool, sunny days and afternoon highs in the mid 60s. As the surface high slides over to the East Coast midweek, return flow will set up again and a gradual warming trend will commence. The next chance of rain looks to arrive next Wednesday night as another weak cold front approaches. CAD && .AVIATION... (00Z TAFS) Issued at 553 PM CST Wed Mar 6 2024 Edge of low-stratus is located east of a line from DYR-MEM-OLV. Some clearing has occurred at MEM in the past hour and necessitated a change from the previous forecast at MEM for the short-term. However, latest hi-res guidance suggests the potential for this low stratus (MVFR/IFR conditions) to move back in overnight at MEM around 8Z and around 12Z at JBR as low-level flow veers NE. MVFR and perhaps IFR conditions expected to be more persistent at MEM/TUP. Ceilings expected to improve by Thursday afternoon. Light winds will gradually veer SE on Thursday. Rain showers have been included at JBR in this TAF set for Thursday afternoon. CJC && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$ PUBLIC FORECAST...CAD AVIATION...CJC
Area Forecast Discussion
National Weather Service Blacksburg VA
1036 PM EST Wed Mar 6 2024 .SYNOPSIS... Low pressure along the Mid-Atlantic Coast will move east and away from the area tonight...the rain gradually coming to an end. After a dry day Thursday, another storm system moves in from the west Friday into Saturday with more rain. && .NEAR TERM /THROUGH THURSDAY/... As of 655 PM EST Wednesday... Key Messages: 1) Rain ends tonight. Patchy fog after midnight. 3) Dry Thursday. Upper low had advanced into central Virginia. Surface low pressure was off the southeast Virginia and coast and the wind has turned to the west over the mountains and foothills. Once the upper low progresses a bit farther northeast, coverage of rain will diminish. No changes to temperature forecast at this time. Previous Discussion As of 655 PM EST Wednesday... Radar showed light rain over a large part of southwest Virginia, northwest North Carolina, and southeast West Virginia. High_res HRRR and other models show little change through 03Z/10PM. Have increased probability of precipitation to account for radar trends through the evening. Expect coverage of rain to diminish after midnight, followed by patchy fog. No changes to temperatures at this time. Previous Discussion As of 230 PM EST Wednesday... Wet Wednesday will transition into a dry Thursday. Low pressure which has provided an abundance of cloud cover and a gentle soaking rain will move east and off the coast tonight. Clouds may linger long enough to prohibit a lot of fog formation, but if there is any clearing, watch out for patchy dense fog. High resolution models suggest best chance of fog and lowest visibility to occur along the western slopes from the WV highlands southwest to along the Cumberland Plateau and from Mt Rogers southwest along the NC/TN border. With lingering clouds, temperatures will change very little with lows ranging from the upper 40s to lower 50s. Thursday will feature a dry day with partial clearing. There will be no significant change in airmass, temperatures remaining relatively mild for the time of year...highs in the 60s. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/... As of 230 PM EST Wednesday... Key Message: 1. Another storm system is expected to impact the area Saturday. Upper ridging will be in place Thursday night and into Friday. Surface high will build over southeast Canada and begin to wedge south along the Appalachians. Low pressure will develop over the Central Plains Friday night and will transition east through Saturday. This will provide another round of rainfall to the region. Friday will be mostly dry with high pressure building in. As the cold air wedge becomes better entrenched throughout the day, could begin to see some upslope clouds and some light rainfall along the eastern slopes of the Blue Ridge as early as Friday evening. Southeast flow will continue to strengthen into Friday night and Saturday morning, so coverage of showers should begin to increase. Saturday will be a raw and rainy day as cold air wedge is maximized. Went below most guidance and especially went below the NBM which was on the warmer side of guidance for highs on Saturday. Perhaps a non diurnal curve will be possible for Saturday, starting warmer early on and cooling as the day progressed. Regardless, highs in the mid/low 40s seems likely with perhaps higher elevations in the 30s. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... As of 230 PM EST Wednesday... Key Messages: 1. Cold front brings cooler temperatures back into the region. 2. Dry high pressure into next week. Primary surface low tracks into Pennsylvania and southern New York by Sunday morning, along with a trailing cold front. Much cooler and gusty at times for Sunday as a strong upper low drops into New England. Could have gusts in the 30 to 40 mph range for the mountains through Sunday night and into Monday morning. Winds begin to taper down through the day Monday as pressure gradient relaxes and low level jet shifts offshore. Heights will begin to build into the mid-week and high pressure begin to build overhead. Temperatures quickly moderate and highs Tuesday/Wednesday will be back to well above normal. && .AVIATION /04Z THURSDAY THROUGH MONDAY/... As of 700 PM EST Wednesday... Closed upper low over North Carolina will lift into Virginia overnight. Widespread IFR to LIFR ceilings are expected through 06Z/1AM along with VFR to MVFR light rain. Once the coverage of rain diminished after midnight, MVFR fog will develop, especially in the mountains and along the western slopes of the central Appalachians as the surface wind turns to the northwest. Patches of IFR to LIFR fog may develop late tonight if there is any clearing. Some breaks in the clouds are expected on Thursday as conditions gradually improve to VFR by afternoon. Surface wind turns back to the north then northeast on Thursday. Average confidence on ceiling, visibility, and wind. .EXTENDED AVIATION OUTLOOK... Dry weather is expected Thursday night and Friday. Another low pressure system arrives late Friday into Saturday with more rain and widespread MVFR to IFR cigs/vsbys, with rain occurring Friday night and most of Saturday. Sunday will be drying out with lingering upslope rain/snow showers over BLF/LWB with windy conditions. Breezy conditions will continue into Monday. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...PM NEAR TERM...AMS/PM SHORT TERM...BMG LONG TERM...BMG AVIATION...AMS/PM
Area Forecast Discussion
National Weather Service Topeka KS
1004 PM CST Wed Mar 6 2024 .KEY MESSAGES... - No significant changes to the forecast. Confidence in the forecast remains high through the weekend. - There is an 80 percent or better chance for showers and thunderstorms Thursday and Thursday night. - Blustery colder conditions move in on Friday. && .DISCUSSION... Issued at 206 PM CST Wed Mar 6 2024 19Z water vapor imagery showed a board cyclonic pattern persisting over the western U.S. A closed low was lifting through the northern plains while another shortwave trough moved onshore along the CA coast. Surface obs showed high pressure ridging into northeast KS at 19Z. But a developing lee trough of low pressure in the central high plains had allowed return flow to develop across western KS. For tonight through Friday there isn`t a lot of change to the forecast. There is a little more concensus from the RAP/NAM/GFS in the warm front lifting into Anderson and Coffey counties by Thursday evening. Even the HREF mean MSLP suggests the warm front lifting into east central KS. The RAP and NAM show the potential for CAPE value to range from 500 to 1000 J/kg along the warm front with 0-6km bulk shear around 40KT. This could be enough for some organized updrafts and perhaps some marginally severe hail late in the afternoon and during the evening. Otherwise widespread rainfall is likely (grater than 80% chance) Thursday and Thursday night. The initial shortwave looks to lift across the forecast area around mid day and the latest CAMs have showers and embedded thunderstorms moving northeast in waves. So it shouldn`t be a constant rainfall but periods of showers and thunderstorms. The NBM mean continues to show rain amounts ranging from 0.75 to 1.5 inches. However the 12Z ECMWF has shifted precip south and east. Think this may be due to a trend in the models taking the main shortwave further south on Friday. The forecast still has rain amounts from around two thirds of an inch over north central KS to near 2 inches in Anderson county. But there could be some risk for lower amounts across the northern counties. The 50th percentile for QPF from the GFS and ECMWF ensembles shows less than a half inch across the northern counties. As for flooding concerns, the latest stream data from the USGS shows the Marais des Cygnes and Neosho river basins are near normal with the northern rivers below normal on stream flow. Plus soils are in the middle 40s and around 50 degrees per the KState mesonet. So rainfall should be able to soak into the soils as long as the rain doesn`t come down to fast. The only other change to the forecast was to lower high temps for Friday. There is good consensus for a strong northernly winds to advect in colder air as precip and cloud cover inhibit insolation. Think temps on Friday may hold steady in the 40s without much of a diurnal change. Surface ridging remains over the area on Saturday keeping temps close to seasonal normals. Then southerly return flow sets up leading into next week with mild and dry weather returning. The forecast as highs around 70 by Monday. The next chance for precip looks to come Tuesday night and Wednesday of next week. While there are still some differences in the models, they are beginning to show a similar idea of a progressive shortwave and frontal boundary moving through. Will have to keep an eye on the quality of the moisture return ahead of the front. && .AVIATION /06Z TAFS THROUGH 06Z FRIDAY/... Issued at 1003 PM CST Wed Mar 6 2024 MVFR and possible IFR conditions with rain moving into the area will impact airports Thursday. Have pushed back the arrival time of these conditions by just an hour or so Thursday morning with the 06Z TAF update. Rain with a chance for isolated embedded thunderstorms will continue for much of the period without much improvement in flight categories until later on Friday. && .TOP WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Wolters AVIATION...Teefey