Area Forecast Discussion
Issued by NWS Des Moines, IA

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070
FXUS63 KDMX 102314
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
614 PM CDT Fri May 10 2024

 ...Updated for the 00z Aviation Discussion...

.KEY MESSAGES...

- Isolated to scattered showers and storms later this afternoon
  and evening. Few strong wind gusts possible, but the severe
  threat is low.

- Periodic rain chances next week, particularly Sunday night
  into Monday and again Wednesday into Thursday. Severe threat
  is low with early week activity, but becomes more uncertain
  toward the middle of next week.

&&

.DISCUSSION...
Issued at 228 PM CDT Fri May 10 2024

GOES water vapor imagery denotes a compact shortwave diving
southeast through Minnesota into Wisconsin. An attendant cold
front was observed stretching from near Duluth and southwestward
through northwest Iowa. This front will continue to sweep
southeast and serve as the focus for isolated to scattered
showers and storms later this afternoon and evening. Boundary
layer moisture will be a significant limiting factor working
against convective coverage and intensity. 19z surface obs show
T-Td spreads approaching 25-30F and cloud bases above 6k feet.
Inverted-v profiles beneath the cloud-bearing layer may favor
sporadic stronger downburst wind gusts with any more robust
updrafts, but overall the severe threat should remain low until
storm chances exit south/east late this evening.

Following a fantastic spring day on Saturday, chances for
showers and storms are quick to return by later day Sunday as a
closed upper low is nudged out of the four corners region and
becomes more of an open and disorganized wave as it moves
through the central Plains. Moisture is pulled northward and
eventually begins competing with a drier airmass impinging from
the north. This leads to some uncertainty on the northern
extent of appreciable precip Sunday night through Monday, and
higher chances have focused across southern and into central
Iowa. Ensemble probs for >1" of precip are highest (~70%) close
to the MO border with diminishing precip amounts to the north.
Any severe threat should be mitigated by lethargic flow aloft
and limited instability.

Mean northwesterly flow aloft dominates through the middle part of
next week as our pattern remains fairly active with additional
opportunities for more rainfall. Precip chances return by late
Tuesday as an upper wave dives southeast out of Canada. Periodic
precip chances are then supported through the remainder of the
forecast as another nearly closed low in the split southern stream
flow is absorbed by the mean northern branch. The severe weather
threat is in questions through the middle of the week due to
uncertainties with the northerly extent and quality of moisture
return off the Gulf of Mexico and the timing of the respective upper
waves crossing the region.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 614 PM CDT Fri May 10 2024

Trough and weak boundary heading southeast across Iowa through
05z. Isolated -shra have formed along the trough while stronger
wind gusts trail the boundary in northern Iowa. Both the showers
and winds will diminish aft sunset with light/var or light
northwest flow through 12z. Some mid level clouds will
continue to near OTM through around 05z. Mixing arrives again
over region aft 15-16z Sat as VFR conditions are maintained
through the period. /rev

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION...Martin
AVIATION...REV