Area Forecast Discussion
Issued by NWS Paducah, KY
Issued by NWS Paducah, KY
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030 FXUS63 KPAH 081738 AFDPAH Area Forecast Discussion National Weather Service Paducah KY 1238 PM CDT Sat Jun 8 2024 .KEY MESSAGES... - Multiple rounds of showers and thunderstorms are forecast today through Sunday afternoon, particularly over southeast Missouri into southern Illinois and far western Kentucky. - Severe weather and flash flooding will be a risk during this time, and a Flood Watch has been issued for much of southeast Missouri from this evening through Sunday afternoon. - Dry and seasonably warm temperatures are expected for much the upcoming week. High temperatures will approach the lower 90s by the end of the work week. && .UPDATE... Issued at 1238 PM CDT Sat Jun 8 2024 Updated aviation discussion for 18z TAFs. && .DISCUSSION... Issued at 305 AM CDT Sat Jun 8 2024 Today through Sunday night...An MCS currently across far eastern KS and far western MO will move into the region as we go into the morning hours. This complex of storms will be in a weakening mode as it makes its approach, so only expecting some light to moderate rain showers and a few rumbles of thunder through early this afternoon. The greatest chance of rain this morning will be across southern IL into southwest IN, with lower chances further to the south. This afternoon, we`ll see some break in the debris cloud cover, allowing temperatures to recover into the middle to upper 80s over southeast MO, southwest IL, and far west KY. Lingering cloud cover will limit high temperatures to the upper 70s to lower 80s further north and east over southeast IL, southwest IN, and the KY Pennyrile. As we go into the mid to late afternoon, a frontal boundary will drift southward into southeast MO, far southern IL, and western KY. This will act as a focal point for additional thunderstorm development going into the evening hours. Short-term model guidance shows 2500-4000 J/kg of SBCAPE developing over much of southeast MO by late this afternoon, along with around 40 kts of 0 to 6 km bulk shear. Isolated to scattered convection will develop near the frontal boundary during this time, with the greatest coverage across southeast MO. A few of these storms could be severe, with damaging winds, large hail, and perhaps a tornado being the main threats. The latest SPC Day 1 Outlook has a marginal risk over southeast MO into parts of southern IL and west KY, but the discussion does mention that an upgrade to a slight risk is possible later today if confidence increases. The storms will grow upscale into clusters tonight and push eastward across the Mississippi River into the rest of the forecast area. With the mean flow parallel to the east-west oriented frontal boundary, multiple rounds of training showers and thunderstorms will be possible this evening through Sunday morning over southeast Missouri. With the potential for several inches of rain here, issued a Flood Watch from 00-18z Sunday for much of southeast Missouri. See the Hydrology section below for more details. Shower and thunderstorm activity will gradually sag south of the region as we go through the day on Sunday, with dry conditions expected by Sunday night. High temperatures Sunday will be a bit cooler than average due to lingering rain chances and clouds, staying the middle to upper 70s in most areas. As high pressure from Canada builds south into the region, skies will clear and a refreshing airmass will arrive. Low temperatures Sunday night will fall into the middle to upper 50s. Monday through Friday...As high pressure from Canada builds southward into the region, an extended period of dry weather is forecast through the upcoming work week. Temperature and humidity levels will be very comfortable by early June standards for the Monday through Wednesday period. High temperatures will reach the upper 70s to lower 80s on Monday and Tuesday, followed by highs in the lower to middle 80s on Wednesday. Dew point temperatures will remain in the 50s during this period, and overnight low temperatures will drop into the 50s in most areas! As the surface high shifts to the east by mid-week, southerly return flow will increase. This will bring hotter and muggier conditions to the region for the latter half of the work week. High temperatures Thursday and Friday will climb into the upper 80s to lower 90s. Dew point temperatures will creep back into the the middle to upper 60s as well. Overnight lows will respond similarly, only falling into the middle to upper 60s. && .AVIATION /18Z TAFS THROUGH 18Z SUNDAY/... Issued at 1238 PM CDT Sat Jun 8 2024 Lingering showers from this morning are now diminishing as a bit of a lull is anticipated before a complex of thunderstorms develops tonight. There is some uncertainty with timing, but KCGI has the greatest risk of seeing TSRA around 04-06z as model guidance has shifted a bit south. Brief MVFR vsbys are also possible with heavier downpours. KPAH is more likely to see SHRA with isolated TSRA not ruled out. Additional SHRA is anticipated through Sunday morning; however, KMVN/KEVV/KOWB are now only likely to see -SHRA if anything with the bulk of pcpn now focused to the south. The other concern will be for MVFR cigs across most terminals after 06-09z with IFR cigs also possible at KCGI where the column will be more saturated. A return to VFR conditions is progged across all northern terminals by 14-16z as a front slowly sags south while the low cigs likely remain in place across the rest of the region. Southerly winds between 5-10 kts turn light & variable tonight. Westerly winds shift northerly between 5-10 kts Sunday morning as a front moves through. && .HYDROLOGY... Issued at 305 AM CDT Sat Jun 8 2024 Synoptic and mesoscale conditions appear to be favorable for multiple rounds of heavy rain over parts of southern and southeast Missouri tonight through Sunday afternoon. Rainfall analysis shows this area has received 150-200% of normal rainfall over the last 30 days. While 100 cm soil moisture remains slightly lower than normal, USGS streamflow analysis shows streams and rivers here are seeing normal to elevated values (50th to 90th percentile). Tonight, showers and thunderstorms will fire along a stalled frontal boundary that will be oriented west to east over the area. PWAT values will range from 1.75 to 2.25" (95th to 99th percentile) near and south of this boundary, and model soundings show a nearly saturated troposphere and a classic "skinny" CAPE profile associated with heavy rain events. With the mean flow forecast to be parallel to the frontal boundary, multiple rounds of showers and thunderstorms could train over the same areas across parts of southeast MO. The 00z/08 HREF is particularly concerning. The mean QPF through Sunday afternoon shows swaths of 1-3" over this area, but the localized probability matched mean product shows pockets of 2-4" with locally higher amounts up to 6" over the Ozark Foothills. If these values are realized, flash flooding, some potentially significant, would be likely here. There remains uncertainly regarding where this axis of heavy rain will set up. The morning MCS that will move through the region could result in this corridor being displaced in any direction, but given the otherwise robust setup for heavy rain and training thunderstorms, confidence was high enough to issue a Flood Watch for much of southeast Missouri. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...None. MO...Flood Watch from 7 PM CDT this evening through Sunday afternoon for MOZ086-087-100-107>112-114. IN...None. KY...None. && $$ UPDATE...DW DISCUSSION...DWS AVIATION...DW HYDROLOGY...DWS