815
FXUS63 KDMX 181722
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1222 PM CDT SUN OCT 18 2026
...UPDATED FOR THE 18Z AVIATION DISCUSSION...
KEY MESSAGES
- BREEZY AND MILD TODAY. SLIGHTLY COOLER WITH LESS WIND ON
MONDAY.
- MOSTLY DRY WITH A WARMING TREND THROUGH THIS WEEK.
SHORT TERM /THROUGH MONDAY NIGHT/
ISSUED AT 209 AM CDT SUN OCT 18 2026
LARGE AREA OF HIGH PRESSURE EXTENDS FROM THE NEW ENGLAND REGION TO
TEXAS THIS MORNING AND THIS SYSTEM WILL CONTINUE TO BE REINFORCED
THROUGHOUT MOST OF THIS WEEK AND REMAIN IN A SIMILAR POSITION. THIS
PATTERN SHUTS OFF ANY GULF MOISTURE TRANSPORT. WEAK RIDGING IS
ONGOING INTO THE REGION IN THE MID-LEVELS AND THIS WILL TRANSITION
TO WEST/SOUTHWEST FLOW AS AN UPPER LOW TO THE SOUTHWEST OF
CALIFORNIA MOVES EASTWARD. THIS TRANSITION WILL LEAD TO SOME PASSING
CIRRUS HIGH LEVEL CLOUDS AS MODEST PACIFIC MONSOONAL FLOW MOISTURE
REACHES THE AREA. FOR TODAY, BREEZY TO GUST SOUTH WIND WITH
TEMPERATURES AGAIN EXCEEDING NBM VALUES. THE LOW LEVEL THERMAL RIDGE
WILL BE OVER THE STATE TODAY AND THAT COMBINED WITH THE DRY AIR
STILL IN PLACE AND GOOD MIXING, WILL RESULT IN THE WARMER THAN
GUIDANCE TEMPERATURES IN THE 60S TODAY. THE 850 MB TEMPERATURES DO
COOL INTO MONDAY AS THE WEAK RIDGING IS FLATTENED BRIEFLY AHEAD OF
THE TRANSITION TO THE WEST/SOUTHWEST FLOW. THE LOWER LEVEL
TEMPERATURES ARE LESS IMPACTED BUT HIGHS WILL BE SLIGHTLY COOLER
THAN TODAY. THE WIND WILL BE LESS AS WELL ON MONDAY AS THE PRESSURE
GRADIENT RELAXES ALONG WITH WEAKER MIXED LAYER WINDS.
LONG TERM /TUESDAY THROUGH SATURDAY/
ISSUED AT 128 PM CDT SAT OCT 17 2026
BY TUESDAY MORNING, A BROAD 500 MB HIGH PRESSURE RIDGE WILL BE
LOCATED OVER MOST OF THE CENTRAL AND EASTERN U.S. HOWEVER, A
WEAK SHORTWAVE WILL BE MOVING OFF THE ROCKIES AND OVER THE HIGH
PLAINS. THIS FEATURE WILL PASS SLOWLY NEAR IOWA ON TUESDAY INTO
WEDNESDAY, BRINGING SOME MID/HIGH LEVEL CLOUDS ACROSS THE REGION
DURING THAT TIME. A FEW MODEL SOLUTIONS EVEN ATTEMPT TO SPIT
OUT LIGHT RAINFALL, HOWEVER, FORECAST SOUNDINGS INDICATE
SUBSTANTIAL DRY AIR IN THE LOWER/NEAR-SURFACE LEVELS WITH FLOW
OUT OF THE GREAT LAKES RIDGE, WHICH SHOULD PRECLUDE ANY
MEANINGFUL CHANCES OF PRECIPITATION. MEANWHILE, DESPITE SOME
INCREASE IN CLOUD COVER, AIRMASS MODIFICATION SHOULD ALLOW FOR
CONTINUATION OF A SLOW WARMING TREND WITH TEMPERATURES PEAKING
IN THE LOWER 70S OR SO ON WEDNESDAY AFTERNOON.
FROM LATE WEDNESDAY INTO FRIDAY A MORE PRONOUNCED 500 MB RIDGE
WILL BUILD OVER THE CENTRAL U.S., INCLUDING IOWA, SUPPORTING
CONTINUED DRY WEATHER AND SLOW WARMING. HIGHS IN THE 70S ARE
FORECAST BOTH THURSDAY AND FRIDAY. EVENTUALLY, BY THE END OF THE
WEEK, A DEEP 500 MB TROUGH WILL MOVE INTO THE WESTERN U.S.
ROCKIES AND BRING A RETURN OF MORE CHANGEABLE WEATHER AND SOME
RAIN CHANCES BY NEXT WEEKEND. ANY DETAILS OF TIMING/LOCATION OF
RAIN CHANCES AND OTHER SENSIBLE WEATHER FIELDS ARE STILL IN FLUX
AT THIS RANGE, BUT WILL STEADILY COME INTO BETTER FOCUS AS THIS
WEEK PROGRESSES.
AVIATION /12Z TAFS THROUGH 12Z MONDAY/
ISSUED AT 1221 AM CDT SUN OCT 18 2026
VFR CONDITIONS WILL CONTINUE FOR THE FORESEEABLE FUTURE. GUSTY
BREEZES THIS AFTERNOON WILL DIMINISH AROUND SUNSET AND BE LIGHT
FROM THE SOUTH TONIGHT THROUGH MONDAY.
DMX WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM...DONAVON
LONG TERM...LEE
AVIATION...LEE
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