####018005162#### FXUS63 KMKX 040246 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 946 PM CDT Fri May 3 2024 .KEY MESSAGES... - A few stronger thunderstorms are possible in southeast WI Saturday afternoon. - Additional showers and thunderstorms are expected during the middle portions of next week. && .UPDATE... Issued 927 PM CDT Fri May 3 2024 Some stratus may move in from Lake Michigan Saturday morning, impacting far eastern Wisconsin. Then some sun is expected there midday before clouds return with the frontal passage. No changes to the shower and thunderstorm chances for Saturday. See previous discussion. Marquardt && .SHORT TERM... Issued 351 PM CDT Fri May 3 2024 Tonight through Saturday night: Clear skies will prevail over southern WI tonight. Look for winds to become light and variable overnight as high pressure moves across the region, then start increasing out of the southeast in the morning as the high departs. Dewpoints mixed down to around 40 this afternoon, so that should help our evening temps drop into the lower 50s quickly. Lows should be in the upper 40s, but can't rule out mid 40s toward central WI. A line of showers and thunderstorms along a weak cold front will be tracking into the western part of WI Saturday morning. This front is associated with a mid level shortwave trough and the resultant weak surface low. The stronger forcing with that shortwave will stick closer to the entrance region of the upper jet, which will track across northwest WI. Therefore, the line of showers with a chance for lightning will be weakening as it tracks into south central WI late Saturday morning. Once the front reaches south central WI from around Janesville to Fond du Lac, there will have been enough daytime heating to allow for some build-up of CAPE (up to 1000 j/kg) in southeast WI to support an increase in shower and thunderstorm development. The shear is on the higher end and will be enhanced by the lake breeze. While the mid level forcing will be weaker, the surface forcing will be stronger. Thus, there is a chance for a stronger storm or two in far southeast WI during the afternoon. Small hail and gusty winds are the threats. The tornado threat is non-zero if storms interact just right with the lake breeze boundary. The window of opportunity looks like 3 to 8 PM for areas between Janesville, Port Washington, and the WI/IL border. Cronce && .LONG TERM... Issued 351 PM CDT Fri May 3 2024 Sunday through Friday: High pressure will take hold of southern WI Sunday and Monday. Look for increasing southeast winds Mon afternoon as low pressure approaches from the Plains. That closed low will stay fairly stationary in the Northern Plains Mon-Tue as it occludes, but showers and thunderstorms along the warm front should extend into southern WI on Tuesday. As the upper low either moves eastward or weakens, another round of showers and storms is possible over southern WI on Thursday. The weather pattern associated with the storm chances is complicated and unorganized, which is the typical nature of upper lows. Expect changes to the forecast many times between now and then. Unfortunately, that upper low does not move out of the Upper Midwest until at least Saturday, which means a prolonged period of clouds and precip chances for southern WI until then. Cronce && .AVIATION... Issued 927 PM CDT Fri May 3 2024 Some clouds may move in from Lake Michigan Saturday morning impacting far eastern Wisconsin, including MKE. Cloud bases could be scattered to broken around 1000ft for a few hours from 10 to 14Z before rising and scattering. There is a lot of uncertainty whether this will occur and VFR could prevail. East winds will become south and gust around 20 knots during the day Saturday for areas inland of Lake Michigan. A line of scattered showers and thunderstorms will be weakening as it moves into south-central Wisconsin late Saturday morning. Once it reaches Janesville to Fond du Lac more widespread showers an thunderstorms are expected to develop late Saturday afternoon and early evening. Marquardt && .MARINE... Issued 351 PM CDT Fri May 3 2024 Light southeast winds are expected tonight into Saturday as high pressure slides across the Upper Great Lakes. Showers and thunderstorms are possible along a cold front late Saturday afternoon through the evening. High pressure will return for Sunday and Monday. The next low pressure system that may bring gusty winds below gale level and another round of thunderstorms will track across northern Lake Michigan Tuesday into Wednesday. Cronce && .MKX WATCHES/WARNINGS/ADVISORIES... WI...None. LM...None. && $$ Visit us at weather.gov/milwaukee Follow us on Facebook, Twitter, and YouTube at: www.facebook.com/NWSMilwaukee www.twitter.com/NWSMilwaukee www.youtube.com/NWSMilwaukee ####018007698#### FXUS61 KBUF 040247 AFDBUF Area Forecast Discussion National Weather Service Buffalo NY 1047 PM EDT Fri May 3 2024 .SYNOPSIS... A weakening cold front will bring some showers to parts of the region this evening into tonight. Shower chances steadily decrease later tonight into Saturday with just scattered showers, and also dry time built in between the showers. Another slow moving cold front will pass across the area Saturday night through Sunday bringing the next round of more widespread showers and possibly a few rumbles of thunder. High pressure then returns Monday, allowing for a dry start to the new work week. && .NEAR TERM /THROUGH SATURDAY/... A weakening occluded front will slowly work across far western New York this evening into tonight. This boundary will bring some light rain showers to the area, with no more than a few hundredths of an inch at best over any given location. As this front progresses east it will begin to fall apart, but there will still be some showers possible for some locales overnight. Otherwise...it will be mild with lows mainly in the 50s. With very little forcing in place for Saturday, expecting just scattered showers, especially during the morning hours with a good deal of dry time built in through the day. Next stronger cold front will approach from the west late Saturday, while next wave moves north from the Ohio Valley. This will help to displace the upper level ridge east over New England, thus opening the door for the next surge of moisture and lift to move over the area with chances for showers increasing from south to north late in the day into the evening. Highs will be mainly in the 60s. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/... The mid-level ridge axis over the forecast area through Saturday afternoon will push east toward New England Saturday night. In its wake, a shortwave trough will track northeast out of the OH/TN Valleys toward WNY. As the trough approaches, shower coverage will increase significantly from south to north through the later portion of Saturday evening and overnight. An influx of moisture with the trough will also help showers expand over the region. There still remains some uncertainty with track of shortwave trough and moisture over the forecast area with some models placing the higher rainfall amounts over WNY and other guidance more to the east toward CNY. An incoming cold front on Sunday morning will increase forcing over the area, prolonging and expanding the potential for showers through at least the afternoon hours. Still uncertainty with how quickly the cold front tracks through the region among guidance as well with some guidance prolonging the showers through most of the day and into the evening on Sunday. Overall though the later portion of Saturday evening through at least the early afternoon on Sunday looks to be soggy for most of the forecast area. The more organized showers on Sunday should be mainly across the eastern third of the area by the late afternoon, with some lingering/scattered showers across the rest of the area. With the large scale trough just north of the region still, along with lingering synoptic moisture, scattered showers will linger through most of Sunday night. Drier air moving into the area along a zonal flow will start to scatter out any remaining showers from west to east through the late night. Rainfall amounts of a quarter of an inch to half an inch is expected, with some higher amounts possible as well. Current thinking is the higher qpf amounts will be along the south shore of Lake Ontario east to the north country. Still plenty of uncertainty with higher qpf placement among guidance still. A ridge building into the region will result in drier weather for Monday through Monday night across the entire area. Clearing skies on Monday will result in increasing sunshine from northwest to southeast through the day. Clouds will linger the longest near the NY/PA line as a disturbance tracks south of the area. Temperatures on Sunday will be in the low 50s for the higher terrain east of Lake Ontario to the mid and upper 60s for the lower elevations south of Lake Ontario. For Monday, temperatures warm to the mid 60s to mid 70s from the higher terrain to lower elevations respectively. && .LONG TERM /TUESDAY THROUGH THURSDAY/... A sprawling mid and upper level low will start out this period over the northern Rockies and Upper Plains states on Tuesday...then will slowly drift eastward across the northern half of the CONUS through the remainder of the work week. This being said...the medium range guidance continues to exhibit considerable differences in the strength and rate of eastward progression of this low...and consequently also in the strength/timing of a number of shortwave impulses ejecting eastward from this system and across our region. With the above in mind...forecast confidence in associated precipitation potential/timing remains fairly low particularly from about Wednesday onward...and as such have undercut blended guidance a bit in an attempt to better reflect this uncertainty. In general this system should bring more unsettled weather with frequent opportunities for showers and perhaps a few thunderstorms during the middle and latter portions of next week...though likely also with some drier periods interspersed. As for temperatures...these will continue to average some 5-10 degrees above normal through this period. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... A weak occluded front will work into the region this evening with lowering VFR Cigs and showers across far western terminals. Flight conditions will slowly deteriorate with MVFR CIGS developing across the Southern Tier (KJHW) tonight, then advancing northward across the Niagara Frontier (KBUF/KIAG) overnight. Mainly VFR conditions expected from the Genesee Valley eastward to include KROC and KART. Saturday...some scattered light showers expected with MVFR CIGS continuing across the Southern Tier (KJHW). KBUF/KIAG should improve to VFR by late morning/midday, with VFR flight conditions expected to continue from KROC east. Outlook... Saturday night and Sunday...VFR/MVFR with showers likely and possible thunderstorms. Monday...VFR. Tuesday and Wednesday...VFR/MVFR. Chance of showers with a slight chance of thunderstorms. && .MARINE... Mainly weak pressure gradients are expected to persist into this weekend across the lower Great Lakes supporting winds to generally remain below 15 knots. Expect this to bring some choppy waters at times, however conditions will remain below headline criteria, especially with an offshore flow developing tonight then persisting through the weekend, keeping the highest waves over Canadian waters for Saturday and Sunday. While quiet weather continues for the end of the work week, a few showers and thunderstorms will be possible tonight through Sunday. High pressure will build across the area for the start of the new work week providing mainly gentle breezes with no more than some light chop expected through Tuesday. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...None. MARINE...None. && $$ SYNOPSIS...AR/JM NEAR TERM...AR/JM SHORT TERM...SW LONG TERM...JJR AVIATION...AR/JM MARINE...AR/JM ####018006079#### FXUS64 KJAN 040249 AFDJAN Area Forecast Discussion National Weather Service Jackson MS 949 PM CDT Fri May 3 2024 ...New MESOSCALE UPDATE... .MESOSCALE UPDATE... Issued at 949 PM CDT Fri May 3 2024 Rest of tonight... Evening RAP analysis/GOES East water vapor imagery indicate shortwave axis moving through the northeastern portions of the region, with rain chances quickly dwindling. In the wake, there is some descent & GOES East total precipitable water (PWs) indicate some drying along the Gulf Coast & to the west. 00Z soundings, especially at SHV, indicate drying in the 700-300mb layer, with lowered mean RH's in this layer progged to spread eastward. This will continue to clear out cloudiness. With continued moist southerly flow gradually decoupling, lows falling into the low- mid 60s, crossover temps will reach nearly 3-6 degrees. This pattern supports low stratus & dense fog developing after midnight across the region. HREF probs >10-30% are widespread & convective allowing models (CAMs) indicate potential for areas of dense fog across the Gulf Coast region. There could be two zones of concern for dense fog, northwest of the Natchez Trace & to the southeast, with some decreased coverage along the Natchez Trace & I-55 corridor. Decided to not get too specific & went ahead with an areawide "Elevated" HWO graphic / Dense Fog advisory. The advisory runs from just after midnight through 9AM Saturday. Updates are out. /DC/ && .DISCUSSION... Issued at 245 PM CDT Fri May 3 2024 Tonight through Sunday night...Isolated to scattered showers and thunderstorms are occuring across much of the area this afternoon, and this will continue before ending from west to east early this evening. Skies may clear some overnight, and with good radiational cooling patchy areas of dense fog will be possible early on Saturday. An HWO graphic will be issued for this potential. Another short wave will move into the area Saturday afternoon and this will kick off another round of shower's and storms. With a little better lapse rate/instability on Saturday, a strong to possibly severe storm cannot be ruled out Saturday afternoon. Little will change on Sunday as moisture continues and yet another in a series of short waves move across the area. Drier air begins to move into the area Sunday night. Highs through the weekend will be in the 80s, with overnight lows in the mid 60s./15/ Monday into Friday...the overall forecast for next week remains similar. Focus will be well above normal/heat early into mid week, potential for severe storms mainly in the Thu-Fri periods, then followed by a marked cool down. The driver for the increasing warmth will be with a pattern shift to more of a ridge influence with the ridge axis over us Mon, then the ridge shifting eastward as we see a powerful system dive across the Rockies and Central Plains. We will be on the western periphery of the low level ridge/high and that will provide a decent S/SW lower level flow to bring in moisture and those well above normal lower level temps. Additionally, we will see capping in play which will keep rain/storm chances more in check. There's some 20-30% type PoPs for Mon-Wed, but this is more due to model variability and I expect this to lower some. The exception could be in the far N, where more proximity to the better lift could allow for better chances. As for severe weather potential...this is mainly looking like potential for a round or two sometime in the Thu/Fri periods. PoPs have come in higher which fits and will follow. Look for chances to continue to increase for a particular period as better timing starts to work itself out. Like yesterday and prev guidance, uncertainty is pretty decent on specifics and timing, which is often the case at day 6-7. However, the pattern and consistency for the needed ingredients (instability, steep lapse rates, moisture, shear, lift) continue to show up. I'll also add, later Wed night is a period to watch as well as there will likely be severe activity on-going to our NW/N which could migrate down into some of our northern area. Lastly, the ingredients I noted are all reaching very solid levels and fitting of a potentially upper end type event(s). Details will determine the type of severe, but at this time, confidence is on wind/hail. In the wake of this system, the trends are for a solid front/trough passage for the weekend which would bring much cooler conditions to the area. /CME/ && .AVIATION... (00Z TAFS) Issued at 734 PM CDT Fri May 3 2024 Other than some light SHRA lingering at GTR/MEI, expect clearing over the next hour. Expect a mixed bag of IFR-LIFR flight categories overnight, with worst flight categorical restrictions from low stratus & some dense fog across the area. Onset timing looks to be around 04/07-09Z before lifting to VFR around 07/14-16Z. Light southerly sfc winds will persist the next 24 hours, sustained up to 10mph & brief higher gusts. Some SHRA & iso TSRA are psbl Saturday aftn, but confidence is too low to introduce in the 00Z TAF cycle. /DC/ && .PRELIMINARY POINT TEMPS/POPS... Jackson 64 86 66 83 / 10 40 30 50 Meridian 63 88 65 87 / 20 40 30 40 Vicksburg 64 86 67 83 / 10 40 30 50 Hattiesburg 65 88 66 87 / 0 30 10 30 Natchez 64 86 65 81 / 0 40 30 50 Greenville 66 84 67 80 / 10 40 40 60 Greenwood 65 84 67 83 / 10 40 40 70 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...Dense Fog Advisory from 1 AM to 9 AM CDT Saturday for MSZ018-019- 025>066-072>074. LA...Dense Fog Advisory from 1 AM to 9 AM CDT Saturday for LAZ007>009- 015-016-023>026. AR...Dense Fog Advisory from 1 AM to 9 AM CDT Saturday for ARZ074-075. && $$ DC/CME/DC