126
FXUS62 KCHS 310747
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
347 AM EDT SAT MAY 31 2025
SYNOPSIS
HIGH PRESSURE WILL BUILD IN OVER THE WEEKEND AND PREVAIL
THROUGH THE MIDDLE OF NEXT WEEK.
NEAR TERM /THROUGH TONIGHT/
TODAY: ALOFT, LONGWAVE TROUGHING WILL ENCOMPASS MUCH OF THE
EASTERN HALF OF THE CONUS WITH A DEEP UPPER LOW ACROSS NEW
ENGLAND AND EASTERN CANADA. AT THE SURFACE, THE FLOW PATTERN
WILL REMAIN CYCLONIC AROUND THE DEEPENING SURFACE LOW MOVING
ACROSS NEW ENGLAND AND THE PRESENCE OF A SURFACE TROUGH LATER IN
THE DAY. OVERALL, THE MAIN STORY OF THE DAY WILL BE A NOTABLY
DRIER AIRMASS AND TEMPERATURES FORECAST TO ACTUALLY BE SLIGHTLY
BELOW NORMAL FOR LATE MAY. LOW-LEVEL WESTERLY FLOW SHOULD ALLOW
US TO OUT PERFORM LOW- LEVEL THICKNESS PROGS AND THE FORECAST
ADVERTISES LOW TO MID 80S ACROSS THE AREA. WESTERLY WINDS WILL
BE A BIT BREEZY, WITH FREQUENT GUSTS UP TO AROUND 20 MPH FROM
MIDDAY ONWARD.
TONIGHT: VERY QUIET CONDITIONS WILL CONTINUE WITH DRIER AND
COOLER AIR IN PLACE. THE FORECAST REMAINS DRY AND LOWS ARE
EXPECTED TO DROP INTO THE LOW 60S AWAY FROM THE IMMEDIATE COAST.
SHORT TERM /SUNDAY THROUGH TUESDAY/
SUNDAY: THE MID-LEVELS WILL CONSIST OF A LONGWAVE TROUGH OVER
THE EAST COAST IN THE MORNING, WITH AN EMBEDDED LOW NORTH OF
NEW ENGLAND. THESE FEATURES SHOULD HOVER IN PLACE THROUGH THE
DAY. OVERNIGHT, THE LOW LIFTS FURTHER NORTH AND WEAKENS, WHILE
A WEAK SHORTWAVE ROUNDS THE BASE OF THE TROUGH, APPROACHING OUR
AREA FROM THE WEST LATE. AT THE SURFACE, WEAK HIGH PRESSURE MAY
BE NEAR THE FL PANHANDLE IN THE MORNING AND THEN IN THE
VICINITY OF OUR AREA IN THE EVENING. ADDITIONALLY, A DISSIPATING
COLD FRONT MAY MOVE THROUGH OUR AREA LATE AT NIGHT. PWATS ~1" IN
THE MORNING SHOULD RISE TO ~1.25" AS TIME PROGRESSES. THESE
VALUES ARE BELOW NORMAL. HENCE, THE DETERMINISTIC MODELS KEEP
OUR AREA FAIRLY DRY, WITH HINTS OF AN ISOLATED SHOWER OR TWO
LATE IN THE DAY ALONG THE SEA BREEZE. BUT GIVEN THE PWATS AND
MODEL SOUNDINGS, IT MIGHT BE HARD TO GET ANY RAINFALL, SO WE
KEPT THE FORECAST DRY. HIGH TEMPERATURES WILL PEAK IN THE MID
TO UPPER 80S, EXCEPT COOLER AT THE BEACHES DUE TO THE SEA
BREEZE. LOWS SHOULD RANGE FROM THE LOWER 60S FAR INLAND TO THE
UPPER 60S/LOWER 70S AT OR NEAR THE BEACHES.
MONDAY: A MID-LEVEL TROUGH WILL STRETCH FROM NEW ENGLAND DOWN
INTO THE SOUTHEAST IN THE MORNING. A SHORTWAVE WILL ROUND THE
BASE OF THIS TROUGH IN THE MORNING AND AFTERNOON, MOVING OVER
OUR AREA. THE TROUGH AXIS SHOULD SHIFT OFFSHORE IN THE EVENING
AND OVERNIGHT, FOLLOWED BY RIDGING BUILDING IN FROM THE WEST. A
SURFACE COLD FRONT SHOULD BE LOCATED JUST TO OUR EAST AND
SOUTHEAST IN THE MORNING, QUICKLY MOVING AWAY. MEANWHILE, HIGH
PRESSURE WILL BE NEAR THE MIDDLE APPALACHIANS. THE HIGH WILL
GRADUALLY MOVE TOWARDS THE MID-ATLANTIC REGION AS TIME
PROGRESSES. PWATS WILL REMAIN ~1.25, WHICH IS STILL BELOW
NORMAL. THE DETERMINISTIC MODELS START OUT DRY, BUT THEN POINT
TOWARDS ISOLATED SHOWERS ALONG THE SEA BREEZE IN THE AFTERNOON.
GIVEN ALL OF THE MODELS GENERALLY HAVE THIS, WE WENT WITH SLIGHT
CHANCE POPS. BUT THE LOW PWATS AND MODEL SOUNDINGS WILL MAKE IT
HARD FOR WIDESPREAD CONVECTION TO DEVELOP. OVERNIGHT WILL BE
DRY. HIGH TEMPERATURES WILL BE IN THE MID 80S TO AROUND 90
DEGREES, EXCEPT COOLER AT THE BEACHES DUE TO THE SEA BREEZE.
LOWS WILL BE AROUND 60 DEGREES FAR INLAND TO THE UPPER
60S/LOWER 70S AT OR NEAR THE BEACHES.
TUESDAY: THE MID-LEVELS WILL CONSIST OF A STRONG RIDGE BUILDING
OVER THE EAST COAST. AT THE SURFACE, HIGH PRESSURE OVER THE
MID-ALANTIC REGION IN THE MORNING WILL SHIFT INTO THE ATLANTIC
LATE IN THE DAY. MODELS HINT THAT PWATS INITIALLY ~1.25" MAY
DROP THROUGH THE DAY. THE DETERMINISTIC MODELS KEEP OUR AREA
FAIRLY DRY, WITH HINTS OF AN ISOLATED SHOWER OR TWO LATE IN THE
DAY ALONG THE SEA BREEZE. BUT THE NBM KEEPS OUR AREA DRY. HIGH
TEMPERATURES WILL BE IN THE MID 80S TO AROUND 90 DEGREES, EXCEPT
COOLER AT THE BEACHES DUE TO THE SEA BREEZE.
LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/
STRONG MID-LEVEL RIDGING WILL PREVAIL BUILD OVER THE SOUTHEAST
U.S. THROUGH THURSDAY, THEN START MOVING OFFSHORE ON FRIDAY.
HIGH PRESSURE IN THE ATLANTIC WILL PREVAIL, USHERING MOISTURE
INTO OUR AREA. THIS PATTERN WILL YIELD DIURNAL CONVECTION.
TEMPERATURES WILL RISE TO ABOVE NORMAL BY FRIDAY.
AVIATION /07Z SATURDAY THROUGH WEDNESDAY/
VFR CONDITIONS ARE EXPECTED TO PREVAIL AT KCHS, KJZI, AND KSAV
THROUGH 06Z SUNDAY.
EXTENDED AVIATION OUTLOOK: VFR.
MARINE
TODAY AND TONIGHT: NORTHWEST WINDS WILL PEAK THIS MORNING THEN
DIMINISH A BIT INTO THE AFTERNOON AS THEY TURN MORE WEST OR
WEST- SOUTHWEST. OTHER THAN A PRE-DAWN PERIOD WHERE GUSTS UP TO
25 KNOTS WILL BE POSSIBLE, SPEEDS SHOULD TOP OUT IN THE 15-20
KNOT RANGE. OVERNIGHT, WINDS ARE EXPECTED TO BE WESTERLY AND NO
HIGHER THAN 15 KNOTS. SEAS SHOULD AVERAGE 2-3 FEET THROUGH THE
PERIOD, WITH UP TO 4 FEET AT TIMES IN THE OUTER WATERS.SATURDAY
WILL SEE BREEZY WEST-NORTHWESTERLY WINDS THROUGHOUT THE MORNING
HOURS, TURNING SOUTHWESTERLY DURING THE AFTERNOON, WITH
STRONGEST WINDS EXPECTED ALONG THE SOUTH CAROLINA NEARSHORE
WATERS AT UP TO 20 KNOTS. WHILE WE CURRENTLY DO NOT HAVE THE
WINDS REACHING SMALL CRAFT ADVISORY CRITERIA ON SATURDAY,
MARINERS SHOULD CHECK BACK BEFORE HEADING OUT AS THE FORECAST
MAY FAVOR STRONGER WINDS. WAVE HEIGHTS OF 2 TO 4 FEET ARE
EXPECTED. WINDS WEAKEN OVERNIGHT INTO SUNDAY AS THEY BECOME
WESTERLY.
EXTENDED MARINE: OUTSIDE OF POTENTIAL DIURNAL CONVECTION, NO
SMALL CRAFT ADVISORIES ARE EXPECTED.
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR
AMZ350.
NEAR TERM...BSH
SHORT TERM...
LONG TERM...
AVIATION...BSH
MARINE...BSH
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