027
FXUS63 KPAH 202308 AAA
AFDPAH

Area Forecast Discussion...UPDATED
National Weather Service Paducah KY
608 PM CDT Thu Jun 20 2024

.KEY MESSAGES...

- Hot and humid conditions will intensify heading into the
  weekend and continue through early next week.

- A weak cold front moving through may spark a few showers and
  thunderstorms late Saturday night into Sunday.

- Another chance for rain arrives next Tuesday night into
  Wednesday. A short break from the 90s and higher humidity is
  anticipated late next week.

&&

.DISCUSSION...
Issued at 216 PM CDT Thu Jun 20 2024

An upper level ridge centered over the Ohio Valley and Eastern U.S.
will continue to intensify across our region Friday into Saturday.
Thereafter, it gets shunted back westward and becomes centered over
the southwest U.S. for much of next week. A shortwave trough will
dig across the Great Lakes into the Upper Ohio Valley this weekend.
This will allow a cold front to sag southward across the Ohio River
Valley on Sunday, leading to some potential for showers and
thunderstorms along it. The main upper support is well northeast of
our cwa though, so overall coverage and intensity of convection may
be marginal at best. Deep layer shear struggles to reach much above
25 kts. There is also a question about how much redevelopment occurs
behind the initial wave of weakening convection that moves in late
Saturday night into Sunday morning. A few stronger storms can`t be
ruled out with the instability and moisture in place during the
afternoon and evening, but it certainly doesn`t look like more
than a low end marginal day.

Winds become northerly briefly later Sunday into early Monday, but
than guidance hints at them switching back around to southerly by
Monday afternoon. While somewhat less humid conditions are possible
on Monday across our northeast counties, the drier airmass likely
fails to make it all the way through the region. Actual air
temperatures may even be a couple of degrees warmer on Monday,
compared to Sunday, due to less cloud cover. The upper ridge tries
to expand back eastward on Tuesday, with 850mb temps modeled at 21-
23C. This very well may be our hottest day of the 7 day period, with
MaxTs reaching the mid to upper 90s.

Another shortwave dives down across the Great Lakes and into the
Ohio Valley Tuesday night into Wednesday. This wave seems to have
more support for more widespread convection along it. A cooler and
drier airmass is then expected to briefly descend across the region
late next week. It appears highs in the upper 80s and dewpoints
falling into the upper 50s to lower 60s is a strong possibility.
Unfortunately, the cooler airmass may be short-lived as there is a
relatively strong signal in the ensemble guidance for the ridge
building back across the mid-Mississippi River Valley on the weekend
of June 29-30. This likely means a return to the 90s along with
increasing humidity.

High temperatures will largely be in the low to mid 90s each day
Friday through next Wednesday, with Tuesday offering the best chance
to be slightly hotter. Dewpoints will range from the mid 60s to
lower 70s most of this time. There likely will be some pooling of
higher moisture ahead of both frontal boundaries, with dewpoints
into the mid 70s in some locations on Sunday and again late next
Tuesday or Wednesday. Heat index values will range from the upper
90s to lower 100s most days, but could exceed 105 in spots on Sunday
and Tuesday. A Heat Advisory may end up being needed across parts of
the region Sunday through Tuesday, whether it be for duration
criteria (100+ heat index for 4 straight days) or 105 for any day.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 608 PM CDT Thu Jun 20 2024

Winds have gone calm across most of the area this afternoon.
Moisture profiles suggest a repeat of last nights fog is
possible at area sites. Will be monitoring for ground fog or
localized areas of IFR visibility but prevailing tempo MVFR is
the forecast for now peaking between 3-6 am. Light southeast
winds are expected during the day Friday.


&&

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...Air Quality Alert until midnight CDT /1 AM EDT/ Friday night
     for INZ081-082-085>088.
KY...None.

&&

$$

DISCUSSION...SP
AVIATION...JGG