152
WTPA42 PHFO 241450
TCDCP2
TROPICAL STORM NOLO DISCUSSION NUMBER 16
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP152026
ISSUED BY NWS NATIONAL HURRICANE CENTER MIAMI FL
500 AM HST THU SEP 24 2026
SATELLITE IMAGES INDICATE THAT NOLO IS GRADUALLY BECOMING BETTER
ORGANIZED, WITH VERY DEEP CONVECTION IN A CURVED BAND ON THE
SOUTHERN AND WESTERN SIDE OF THE CIRCULATION. ADDITIONALLY, A GPM
PASS FROM OVERNIGHT INDICATED THAT AN INNER CORE IS FORMING,
ALTHOUGH THE EASTERN SIDE IS FRAGMENTED. INTENSITY ESTIMATES ARE
RISING, AND THE CURRENT WIND SPEED IS SET TO 50 KT AS A BLEND OF
THE LOWER SUBJECTIVE AND HIGHER OBJECTIVE VALUES.
NOLO HAS NOT MOVED MUCH DURING THE LAST SEVERAL HOURS BUT SHOULD
BEGIN TO MOVE NORTHWARD AND NORTH-NORTHEASTWARD LATER TODAY DUE TO
A MID-LATITUDE TROUGH DROPPING OVER THE NORTHWESTERN HAWAIIAN
ISLANDS. THE TROUGH IS FORECAST TO MOVE WESTWARD BY SATURDAY WITH
A BUILDING RIDGE NORTH OF THE MAIN HAWAIIAN ISLANDS, CAUSING A
SHARP WESTWARD TURN THIS WEEKEND. THE BIG QUESTION IS HOW CLOSE
DOES NOLO GET BEFORE MAKING THAT TURN, WITH NOTABLE RUN-TO-RUN
INCONSISTENCIES IN MUCH OF THE GUIDANCE. SIMILAR TO THE LAST
CYCLE, THE BULK OF THE MODELS HAVE SHIFTED SLIGHTLY NORTHWARD, AND
THE NEW NHC FORECAST IS MOVED IN THAT DIRECTION. THIS REMAINS A
MORE UNCERTAIN FORECAST THAN NORMAL GIVEN THE LARGE UNRESOLVED
NORTH-SOUTH SPREAD, WITH OTHER POSSIBLE COMPLICATING TERRAIN
INFLUENCES OF THE BIG ISLAND (LIKE WE SAW WITH HURRICANE LALA LAST
MONTH). THEREFORE, THE LONG-RANGE PORTION OF THE FORECAST IS
ESSENTIALLY UNCHANGED.
WITH THE FORMATION OF AN INNER CORE, CONDITIONS APPEAR TO BE COMING
TOGETHER FOR RAPID INTENSIFICATION GIVEN THE OTHER CONDUCIVE
ENVIRONMENTAL FACTORS OF WARM SSTS, LOW SHEAR AND HIGH MID-LEVEL
MOISTURE. NOLO IS LIKELY TO BECOME A HURRICANE BY TONIGHT AND
REACH MAJOR HURRICANE STRENGTH AS IT NEARS THE BIG ISLAND ON
SATURDAY. THE NEW FORECAST IS RAISED FROM THE PREVIOUS ONE, JUST
BELOW THE HCCA AID, WHICH HAS DONE WELL THIS YEAR IN THESE
STRENGTHENING EPISODES. NOTE THAT A TRACK CLOSER TO THE BIG ISLAND
COULD SUBSTANTIALLY INCREASE THE THREAT OF DAMAGING WINDS,
PARTICULARLY OVER HIGHER TERRAIN, ALONG EXPOSED RIDGES, AND IN AREAS
DOWNWIND OF THE RIDGES.
KEY MESSAGES:
1. NOLO IS EXPECTED TO STRENGTHEN INTO A HURRICANE TODAY AS IT
MOVES NORTHWARD TO NORTH-NORTHEASTWARD, POTENTIALLY MAKING ITS
CLOSEST APPROACH TO THE BIG ISLAND OF HAWAII AS A MAJOR HURRICANE ON
SATURDAY. A HURRICANE WATCH REMAINS IN EFFECT FOR THE BIG ISLAND,
AND RESIDENTS THERE SHOULD FOLLOW ADVICE GIVEN BY LOCAL OFFICIALS,
INCLUDING EVACUATING IF TOLD TO DO SO. A HURRICANE WARNING WILL
LIKELY BE REQUIRED FOR THE BIG ISLAND LATER TODAY.
2. THE TIME TO FINISH PREPARATIONS FOR SIGNIFICANT HEAVY RAIN
AND FLOODING IMPACTS ON THE BIG ISLAND IS NOW AS HEAVY RAIN
INCREASES IN BOTH COVERAGE AND INTENSITY TODAY AND FRIDAY. PERIODS
OF HEAVY RAIN ARE EXPECTED TO CONTINUE ACROSS THE BIG ISLAND AND
MAUI THROUGH THE WEEKEND. LIFE-THREATENING, CATASTROPHIC FLOODING
AND MUDSLIDES ARE POSSIBLE, ESPECIALLY IN AREAS OF STEEP TERRAIN
ACROSS THE BIG ISLAND AND MAUI. ACROSS THE REMAINDER OF HAWAII,
LESSER RAINFALL TOTALS ARE EXPECTED, WITH ISOLATED FLOODING
POSSIBLE.
3. LARGE AND DAMAGING WAVES ARE POSSIBLE ALONG PORTIONS OF THE
BIG ISLAND'S COASTLINE INTO THE WEEKEND.
4. INTERESTS ELSEWHERE IN HAWAII SHOULD CLOSELY MONITOR THE
LATEST FORECAST UPDATES AND ENSURE THAT THEY HAVE THEIR PREPAREDNESS
PLANS IN PLACE. TROPICAL STORM WATCHES MAY BE REQUIRED FOR OTHER
ISLANDS LATER TODAY OR ON FRIDAY.
FORECAST POSITIONS AND MAX WINDS
INIT 24/1500Z 14.9N 156.2W 50 KT 60 MPH
12H 25/0000Z 15.2N 156.2W 65 KT 75 MPH
24H 25/1200Z 16.1N 155.8W 80 KT 90 MPH
36H 26/0000Z 17.1N 155.4W 95 KT 110 MPH
48H 26/1200Z 17.8N 155.4W 100 KT 115 MPH
60H 27/0000Z 18.0N 156.4W 105 KT 120 MPH
72H 27/1200Z 18.1N 158.2W 105 KT 120 MPH
96H 28/1200Z 19.0N 162.0W 105 KT 120 MPH
120H 29/1200Z 21.6N 164.4W 90 KT 105 MPH
FORECASTER BLAKE
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