Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
006 FXUS63 KMKX 131903 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 203 PM CDT Fri Sep 13 2024 .KEY MESSAGES... - Unseasonal summer-like temperatures continue into next week with daily highs running 5 to 15 degrees above normal. Not out of the question to see high approach or even exceed 90F Sunday-Tuesday. - Isolated to widely scattered showers and even a low end potential for thunderstorms will be possible Saturday and Sunday (15-30%). && .SHORT TERM... Issued 205 PM CDT Fri Sep 13 2024 Tonight through Sunday night: Summer-like pattern continues through the weekend as the upper- level rex blocking pattern persists with daily highs running 5 to 15 degrees above normal for this time of year. Will see the high clouds from the outer edges of the tropical system remnants clip southern WI through the evening and linger into Saturday. This will help keep temps slightly cooler, but still well above normal. With any breaks in the clouds will see even warmer temps likely exceeding the current forecast highs. Overnight temps will run warmer as well with nightly lows only dipping into 60s through the weekend. Similar if not slightly warmer temps are expected for Sunday with highs topping off in the low to mid 80s. While the upper-level ridge/high pressure persists over the Great Lakes Region, it looks to be strong enough to block the remnants of the tropical system to making up this far north. However, most models prog a piece of the mid-level vorticity to break off from the main trough and work its way up the western peripheral of the upper- level ridge. This bit of forcing paired with increasing dewpoints around 60F and in the low 60s and PWATs exceeding 1-1.5 inches, may be enough to trigger a few isolated showers across southwest to south-central WI Saturday and Sunday, but the better chances look to be further west in IA/MN. While most CAMs show this type of activity to develop and scrape our western CWA, overall it does not look to amount to much in the way of rainfall and coverage for our neck of the woods. Nevertheless, will need to monitor as the 12z HREF does depict some low-end instability (SBCAPE 250-750 J/kg) to build over areas west of I-39/90 corridor through Saturday afternoon and cannot rule out an isolated to widely scattered thunderstorm or two for Saturday afternoon. Shower chances (<30%) will linger into Sunday as this piece of mid-level vorticity works its way across the region along with increasing moisture, but confidence is lower given the departing forcing. Wagner && .LONG TERM... Issued 205 PM CDT Fri Sep 13 2024 Monday through Friday: Predominantly dry weather is anticipated throughout the extended forecast period. Models agree with the blocking pattern keeping an upper level ridge and high pressure overhead with more activity to the west in more low pressure areas. The low pressure system is projected to start moving into the region by the end of next week, however current models show discrepancies regarding the exact timing of this systems arrival. We will see an increase in humidity levels as we move into the upcoming week. This increase in moisture content is expected to result in some cloudy conditions throughout the week. Low temperatures will be in the upper 50s to low 60s. High temperatures will be in the upper 70s to mid-80s, remaining about 10- 15 degrees above average for the month of September. Maile && .AVIATION... Issued 205 PM CDT Fri Sep 13 2024 Outside of some high cirrus clouds from remnants of the tropical system, VFR conditions will prevail through the period with high pressure settled over the northeast CONUS. This will result in prevailing easterly winds 5-10 knots through the afternoon before weakening this evening as winds decouple. Expect these clouds to linger for Saturday with more southeasterly winds as the high gradually slides a bit more east. While expecting a predominately dry forecast, cannot rule out seeing a few isolated to widely scattered showers and even a rumble of thunder or two Saturday afternoon/evening terminal along and west of the I-39/90 corridor. Wagner && .MARINE... Issued 205 PM CDT Fri Sep 13 2024 Broad area of high pressure has settled over the Hudson Bay region and expands south across all of the Great Lakes Region. Lake Michigan is situated on the southern edge of this high pressure with the remnants of the tropical system over the mid- Mississippi River Valley resulting in prevailing breezy easterly winds through tonight. High pressure slowly slides east through the weekend and into early next week with winds turning from easterly to more southerly by mid week. Pattern looks to shift toward the middle to end of next week as low pressure develops over the the Central Plains. Wagner && .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