Area Forecast Discussion Issued by NWS Houston/Galveston, TX
000
FXUS64 KHGX 172046
AFDHGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
346 PM CDT MON JUN 17 2013
.DISCUSSION...
A TYPICAL SUMMER PATTERN THROUGH THE WEEK...A DAY-BY-DAY REPEAT
PERFORMANCE OF NEAR 20 DEGREE INTERIOR DIURNAL TEMPERATURE SWINGS
...10 DEGREES OVER COASTAL AREAS...UNDER MOSTLY TO PARTLY CLOUDY
CANOPIES. LOWER LEVEL (UNDER 85H) MOISTURE LEVELS WILL STAY
CONSISTENTLY HIGH PER A PERSISTENT ONSHORE FLOW...BUT SIGNIFICANTLY
DRIER 6-8H MID-LEVELS WILL MOST LIKELY BE THE REASON FOR THE SHORT
EXISTENCE OF ANY EVOLVING SHOWER. PRECIPITATION WILL BE ON THE
LOW SIDE...PRIMARILY TO ACCOUNT FOR THE VERY LOW AREAL COVERAGE...BUT
CONFIDENCE IS HIGHER IN (RANDOM) OCCURRENCE. REASONING IS THE SAME
AS IT USUALLY IS FOR THIS TIME OF YEAR...HIGH LOWER LEVEL MOISTURE
WITH ACHIEVABLE CONVECTIVE TEMPERATURES BY LATE MORNING ALL WITHIN
AN UNSTABLE (OR WEAKLY-CAPPED) EARLY DAY ENVIRONMENT. THE HIGHEST
TUE-WED POPS WILL RESIDE OVER THE FAR INTERIOR COMMUNITIES (NORTHERN
INFLUENCE OF MCS ACTIVITY) AND NEAR THE COAST (DUE TO SEA BREEZE
AND/OR SPEED CONVERGENCE).
WESTERN UPPER RIDGING APPEARS TO NOT WANT TO FULLY ASSERT ITSELF
OVER THE STATE...ITS AXIS REMAINING FAR OFF TO THE WEST OVER THE
DESERT SOUTHWESTERN STATES. A SLIGHT `DIP` IN HEIGHTS OVER THE
ARKLATEX WILL LIKELY BE THE IMPETUS TO UNSETTLED WEATHER THROUGH
MID-WEEK. THESE WEAKER HEIGHTS...OR WEAK TROUGHING DEVELOPING ALONG
THE NORTHEASTERLY PERIPHERY OF THE NORTHERN MEXICO RIDGE...WILL
KEEP AT LEAST SLIGHT POPS IN THE NEAR TERM (DAYTIME) FORECAST.
ALTHOUGH THERE ARE TIMING ISSUES...THE MODELING SUITE WANTS TO
PUSH REGIONS OF HIGHER PVA ACROSS OKLAHOMA/RED RIVER VALLEY
THROUGH MID-WEEK. THUS...A HIGHER PROBABILITY OF RETURNING
NORTHERN-BASED MCS`S AFFECTING OUR NORTHERN COUNTIES...OR NORTHERN
CONVECTION OUTFLOW SAGGING INTO OUR AREA DURING THE WARMTH OF THE
DAY...WILL KEEP AT LEAST 20-30 POPS IN PLACE UNTIL THIS SOUTHWESTERN-
BASED RIDGE FINALLY DECIDES TO BUILD IN OVER THE STATE (MAYBE LATE
IN THE WEEK?). IF THIS DOES OCCUR...THEN A MORE UNSETTLED MID-WEEK
PATTERN WILL TRANSITION TO MORE SUNSHINE AND SLIGHTLY WARMER
AFTERNOONS JUST BEFORE FRIDAY`S SUMMER SOLSTICE (1204 AM CDT). IF
HIGHER HEIGHTS DO NOT OCCUR...THEN EXPECT A MORE CUT-AND-PASTE
FORECAST FROM MID-WEEK.
THE LATE PERIOD SITUATION IS ONE OF AN UNSETTLED GULF
PATTERN...LOWERING MID-LEVEL HEIGHTS WITH NO SIGNIFICANT (NEAR)
SURFACE LOWERING PRESSURES. AN ILL-DEFINED INVERTED 5H TROUGH (OR
WEAK CLOSED-OFF LOW) OVER THE EASTERN GULF IS CURRENTLY PROGGED TO
BRING AMPLE RAIN TO THOSE WATERS/FLORIDA. TEXAS FALLS ON THE MORE
SUBSIDENT SIDE OF THIS FEATURE EARLY NEXT WEEK. THE UNCERTAINLY OF
WHERE THIS TROUGH AXIS EVENTUALLY SETS UP HAS 20-30 POPS OVER THE
INTERIOR SUNDAY AND MONDAY....BASICALLY KEEPING THE ANTENNA UP FOR
A POSSIBLE PATTERN CHANGE (PER THIS RETURNING UNSETTLED GULF
SCENARIO). 31
&&
.MARINE...
LIGHT TO MODERATE ONSHORE WINDS WILL PERSIST FOR MUCH OF THE
WEEK AND ON INTO THE WEEKEND. IN GENERAL...STILL EXPECTING
SMOOTH TO SLIGHTLY CHOPPY BAY WATERS...1 TO 3 FOOT SEAS...AND
SOUTH TO SOUTHEAST WINDS IN A 5 TO 15 KNOT RANGE. 42
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 76 95 75 95 75 / 20 30 20 20 10
HOUSTON (IAH) 75 95 75 94 75 / 10 20 20 20 10
GALVESTON (GLS) 80 90 80 90 80 / 10 10 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...31/42