Area Forecast Discussion
Issued by NWS St. Louis, MO

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KLSX 261056
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
556 AM CDT WED AUG 26 2015

.SHORT TERM:  (THROUGH LATE THIS AFTERNOON)
ISSUED AT 249 AM CDT WED AUG 26 2015

EARLY THIS MORNING...OUR REGION REMAINS SANDWICHED BETWEEN AN UPPER
LOW NEAR JAMES BAY CANADA AND AN UPPER LEVEL RIDGE CENTERED OVER
EASTERN CO/NM...RESULTING IN NW FLOW ALOFT FOR OUR REGION.  A
SURFACE HIGH PRESSURE RIDGE CONTINUES TO DOMINATE THE MIDWEST...WITH
THE AXIS FROM MN-MO...RESULTING IN A LIGHT NW FLOW FOR OUR REGION.
SATELLITE DATA SHOWS CLEAR SKIES FOR MUCH OF OUR REGION...BUT WITH
THE WESTERN EDGE OF A LARGE AREA OF CLOUDS CLIPPING PARTS OF CENTRAL
AND SOUTHERN IL.  TEMPERATURES AT MOST LOCALES WERE IN THE 50S.

NW FLOW ALOFT ABSENT OF UPPER LEVEL DISTURBANCES WILL PERSIST
TODAY...AS THE SURFACE HIGH PRESSURE RIDGE AXIS CROSSES THRU OUR
REGION AND PASSES JUST TO THE EAST BY NIGHTFALL.  THIS WILL
EFFECTIVELY MAINTAIN THE CURRENT DRY ATMOSPHERIC COLUMN AND LEAVE US
WITH ANOTHER DRY DAY.  ONLY REAL ISSUE IS HANDLING OF CLOUDS IN
IL...WITH THIS AFFECTING THE SOUTHWESTERN IL COUNTIES THRU EARLY
MORNING AND SHOULD SCATTER OUT AS PART OF A LARGER DIURNAL CUMULUS
CLOUD FIELD THAT DEVELOPS BY MIDDAY AND REMAINS MAINLY E OF THE MS
RIVER.  DESPITE THE ONLY REAL CHANGE FROM PERSISTENCE BEING THESE
ADDITIONAL CLOUDS IN IL...THEIR EFFECT ON TEMPS IS EXPECTED TO BE
MINIMAL...WITH PERSISTENCE TEMPS BEING THE RULE ONCE AGAIN FOR THIS
AFTERNOON WITH MAXES IN THE UPPER 70S TO AROUND 80.

TES

.LONG TERM:  (TONIGHT THROUGH TUESDAY)
ISSUED AT 249 AM CDT WED AUG 26 2015

MUCH OF THE FCST REMAINS SIMILAR TO THE PREV. SFC RIDGE BEGINS TO
MOVE OUT OF THE REGION THURS AS THERMAL RIDGE BUILDS INTO THE AREA
AHEAD OF APPROACHING SYSTEM. WITH STRONG THE WAA...CURRENT FCST
TEMPS FOR FRI MAY NOT BE WARM ENUF. HOWEVER...WITH QUESTIONS
REGARDING CLOUD COVERAGE AND PRECIP...HAVE TRENDED TWD THE WARMER
GUIDANCE. MDLS CONTINUE TO SUGGEST LITTLE IN THE WAY OF PRECIP WITH
THIS SYSTEM AND HAVE THEREFORE KEPT POPS IN THE LOW CHANCE RANGE OR
LOWER THRU SAT.

FOR THE EXTD...MDLS ARE IN GOOD AGREEMENT WITH THE UPPER TROF MOVING
EWD OUT OF THE REGION BY SUN. HEIGHT RISES AND SLY FLOW AT THE SFC
SHUD RESULT IN DAYTIME TEMPS SEASONAL AVG THRU MID WEEK.

TILLY

&&

.AVIATION:  (FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 555 AM CDT WED AUG 26 2015

VFR CONDITIONS...DRY WX...AND LIGHT SURFACE WINDS WILL PREVAIL AT
THE TAF SITES THRU THE VALID PERIOD. ONCE AGAIN...STEAM FOG WILL
BE A SHORT-LIVED THREAT FOR THE TAF SITES NEAR RIVERS (SUS AND
CPS) BUT PROBABILITIES OF IT HAPPENING ARE LOW ENOUGH TO PRECLUDE
MUCH IN THE WAY OF A MENTION MORE THAN VCFG.

TES

&&

.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&

$$

WFO LSX



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.