337
FXUS64 KTSA 181937
AFDTSA

Area Forecast Discussion
National Weather Service Tulsa OK
237 PM CDT Fri Apr 18 2025

...New SHORT TERM, LONG TERM...

.KEY MESSAGES...
Updated at 216 PM CDT Fri Apr 18 2025

  - Multiple rounds of strong to severe thunderstorms are expected
    this evening and through the weekend. All severe hazards are
    possible, with large hail being the most likely hazard type.

  - Prolonged heavy rainfall will likely result in areas of flash
    flooding and main stem river flooding this weekend.

  - Drier weather returns early next week, but unsettled weather
    resumes by midweek.

&&

.SHORT TERM...
(Through tonight)
Issued at 216 PM CDT Fri Apr 18 2025

A surface cold front is pushing southeast into the area, faster than
what most model guidance had been indicating previously. This
discrepancy casts some uncertainty into the short term forecast,
as models continue to lag behind what is being observed. With that
said, the cold front should at least make it to through I-44
corridor by late afternoon, settling somewhere in a SW-NE line
from east- central OK into northwest AR. With all of that said, as
instability spreads in aloft, along with peak heating, some storm
formation is expected by the early evening along or ahead of the
front. This will probably place the initial activity southeast of
I-44, some of which is expected to become severe. Storms will be
capable of all hazards, but large damaging hail or strong winds
are the favored threats.

Additional rounds of elevated storms will develop and move across
the area overnight, which may help to strengthen and force the cold
front boundary further south. Large hail is expected to be the
dominant severe hazard with these storms. This will continue
through Saturday morning. A few areas of flash flooding could
develop under training storms, and a Flood Watch is in effect to
cover this possibility. Low temperatures tonight will be in the
50s along and northwest of the I-44 corridor, and 60s-70s to the
south where the front will not penetrate as deeply.

&&

.LONG TERM...
(Tomorrow through Friday)
Issued at 216 PM CDT Fri Apr 18 2025

The frontal boundary may retreat back north on Saturday to near
the I-44 corridor. Strong and diffluent flow aloft continues
through the day Saturday, with a low level jet advecting warm and
humid air into the region. Given moisture levels will be near the
climatological max for this time of year, widespread moderate to
heavy rain will continue to regenerate. Although instability will
wain to some degree due to the continuous overturning, scattered
thunderstorms are likely. Areas closer to or south of the front,
or areas with less persistent rainfall may see additional severe
weather Saturday. Of possibly greater concern will be rainfall
totals, which may become significant by Saturday. The SPC has
maintained a slight risk (15-30% chance) for severe weather
Saturday, with the WPC showing a moderate risk (25-40% chance) of
excessive rainfall leading to flash flooding. Saturday will be
quite cool given the persistent rains. Areas that stay northwest
of the boundary may stay in the 50s, with mid 60s south of the
boundary, except in far southeast OK and west-central AR where it
will be a bit warmer.

The upper level low will pass over the area Sunday, along with
the associated surface low. This will result in one last punch of
rain, with a few thunderstorms as well. Storm total rainfall will
range from 2-4", locally up to 6" for most areas. Totals will be a
bit lower in far southeast OK, perhaps 1-2". By Sunday, in
addition to the flash flood potential, main stem rivers will be
rising. With several rivers expected to reach at least minor flood
stage, possibly higher if corridors of heavy rainfall line up
favorably with river basins. Cooler and drier air finally moves in
Sunday afternoon. Skies will clear with highs into the 60s to near
70 F.

Monday will be a break from the action, with highs jumping into the
mid 70s, mostly sunny skies, and light southerly wind. Things will
begin to change by Tuesday as southwesterly flow aloft returns along
with a healthy southerly low level jet. Showers and thunderstorms
may return to the area as soon as Wednesday morning, but if not,
then by later Wednesday into Thursday. Daily storm chances will
continue through the end of the forecast period, with at least
some daily potential for severe weather and heavy rain.

&&

.AVIATION...
(18Z TAFS)
Issued at 1225 PM CDT Fri Apr 18 2025

Cold front moving into northeast OK this afternoon should be in
vcny of I-44 by 00z. A few light showers remain possible through
the afternoon and may see at least brief MVFR conditions along and
north of the front. Expectation remains for showers and
thunderstorms to increase near the frontal boundary in NE OK by
around 00z and eventually spread south and east through the late
evening. Probability of MVFR conditions becomes higher after 06z
tonight, especially north of the front at NE OK sites. Widespread
showers and thunderstorms will likely persist through much of
Saturday.

&&

.PRELIMINARY POINT TEMPS/POPS...
TUL   56  64  57  70 / 100  90 100 100
FSM   67  77  64  76 /  70  70  90  90
MLC   63  74  62  73 /  90  90  90  90
BVO   53  59  53  69 / 100  90 100 100
FYV   63  70  59  73 /  90  90  90  90
BYV   62  70  59  73 /  90  80  90  90
MKO   61  68  60  72 /  90  90 100  90
MIO   56  61  58  70 / 100  90 100 100
F10   59  66  59  71 / 100 100 100  90
HHW   67  78  63  73 /  70  60  80  90

&&

.TSA WATCHES/WARNINGS/ADVISORIES...
OK...Flood Watch from 7 PM CDT this evening through Sunday evening
     for OKZ054>076.

AR...Flood Watch from 7 PM CDT this evening through Sunday evening
     for ARZ001-002-010-011-019-020-029.

&&

$$

SHORT TERM...06
LONG TERM....06
AVIATION...14