Eastern North Pacific Tropical Weather Outlook
901
ABPZ20 KNHC 130531
TWOEP
Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 PM PDT Sat Sep 12 2026
For the eastern and central North Pacific east of 180 longitude:
Active Systems:
The National Hurricane Center is issuing advisories on Tropical
Storm Norbert, located well west of the southern tip of the Baja
California Peninsula.
Central and Western East Pacific (EP97):
An area of low pressure located several hundred miles southwest of
the southwestern coast of Mexico is producing disorganized showers
and thunderstorms, displaced to its south and east. Environmental
conditions remain conducive for development, and a tropical
depression is expected to form during the next couple of days while
it moves generally west-northwestward to westward over the central
and western portions of the eastern Pacific basin. For more
information, including gale warnings, please see the High Seas
Forecast issued by the National Weather Service.
* Formation chance through 48 hours...high...80 percent.
* Formation chance through 7 days...high...90 percent.
Well Southeast of the Hawaiian Islands:
A broad area of low pressure located several hundred miles southeast
of Hilo, Hawaii, is producing minimal shower activity. Development
of this system is no longer expected.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...low...near 0 percent.
&&
High Seas Forecasts issued by the National Weather Service
can be found under AWIPS header NFDHSFEPI, WMO header FZPN02
KWBC, and on the web at ocean.weather.gov/shtml/NFDHSFEPI.php
$$
Forecaster Adams
Summary for Tropical Storm Norbert (EP4/EP142026)
...NORBERT STRENGTHENS SLIGHTLY... ...EXPECTED TO DISSIPATE WELL EAST OF HAWAII BY THE MIDDLE OF NEXT WEEK... As of 11:00 PM HST Sat Sep 12 the center of Norbert was located near 18.0, -131.7 with movement W at 12 mph. The minimum central pressure was 1000 mb with maximum sustained winds of about 50 mph.
Tropical Storm Norbert Public Advisory Number 15
Issued at 1100 PM HST Sat Sep 12 2026341 WTPZ34 KNHC 130848 TCPEP4 BULLETIN Tropical Storm Norbert Advisory Number 15 NWS National Hurricane Center Miami FL EP142026 1100 PM HST Sat Sep 12 2026 ...NORBERT STRENGTHENS SLIGHTLY... ...EXPECTED TO DISSIPATE WELL EAST OF HAWAII BY THE MIDDLE OF NEXT WEEK... SUMMARY OF 1100 PM HST...0900 UTC...INFORMATION ----------------------------------------------- LOCATION...18.0N 131.7W ABOUT 1450 MI...2330 KM W OF THE SOUTHERN TIP OF BAJA CALIFORNIA ABOUT 1530 MI...2465 KM E OF HILO HAWAII MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H PRESENT MOVEMENT...W OR 280 DEGREES AT 12 MPH...19 KM/H MINIMUM CENTRAL PRESSURE...1000 MB...29.53 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. DISCUSSION AND OUTLOOK ---------------------- At 1100 PM HST (0900 UTC), the center of Tropical Storm Norbert was located near latitude 18.0 North, longitude 131.7 West. Norbert is moving toward the west near 12 mph (19 km/h), and this motion is expected to continue during the next few days. Maximum sustained winds are near 50 mph (85 km/h) with higher gusts. Some fluctuations in intensity remain possible over the next day or so, followed by a gradual weakening trend. Tropical-storm-force winds extend outward up to 80 miles (130 km) from the center. The estimated minimum central pressure is 1000 mb (29.53 inches). HAZARDS AFFECTING LAND ---------------------- None. NEXT ADVISORY ------------- Next complete advisory at 500 AM HST. $$ Forecaster Pierce/Gibbs
Tropical Storm Norbert Forecast Advisory Number 15
Issued at 0900 UTC SUN SEP 13 2026000 WTPZ24 KNHC 130847 TCMEP4 TROPICAL STORM NORBERT FORECAST/ADVISORY NUMBER 15 NWS NATIONAL HURRICANE CENTER MIAMI FL EP142026 0900 UTC SUN SEP 13 2026 TROPICAL STORM CENTER LOCATED NEAR 18.0N 131.7W AT 13/0900Z POSITION ACCURATE WITHIN 30 NM PRESENT MOVEMENT TOWARD THE WEST OR 280 DEGREES AT 10 KT ESTIMATED MINIMUM CENTRAL PRESSURE 1000 MB MAX SUSTAINED WINDS 45 KT WITH GUSTS TO 55 KT. 34 KT....... 70NE 30SE 20SW 70NW. 4 M SEAS....120NE 45SE 60SW 120NW. WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT. REPEAT...CENTER LOCATED NEAR 18.0N 131.7W AT 13/0900Z AT 13/0600Z CENTER WAS LOCATED NEAR 17.9N 131.2W FORECAST VALID 13/1800Z 18.3N 133.5W MAX WIND 45 KT...GUSTS 55 KT. 34 KT... 70NE 10SE 20SW 70NW. FORECAST VALID 14/0600Z 18.8N 135.8W MAX WIND 45 KT...GUSTS 55 KT. 34 KT... 70NE 10SE 20SW 70NW. FORECAST VALID 14/1800Z 19.1N 138.5W MAX WIND 40 KT...GUSTS 50 KT. 34 KT... 60NE 0SE 0SW 60NW. FORECAST VALID 15/0600Z 19.4N 141.1W MAX WIND 35 KT...GUSTS 45 KT. 34 KT... 50NE 0SE 0SW 50NW. FORECAST VALID 15/1800Z 19.5N 144.0W...POST-TROP/REMNT LOW MAX WIND 30 KT...GUSTS 40 KT. FORECAST VALID 16/0600Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 18.0N 131.7W NEXT ADVISORY AT 13/1500Z $$ FORECASTER PIERCE/GIBBS
Tropical Storm Norbert Forecast Discussion Number 15
Issued at 1100 PM HST Sat Sep 12 2026000 WTPZ44 KNHC 130849 TCDEP4 Tropical Storm Norbert Discussion Number 15 NWS National Hurricane Center Miami FL EP142026 1100 PM HST Sat Sep 12 2026 Norbert's convective organization has improved during the past several hours. A renewed burst of deep convection, with cloud-top temperatures as cold as -80 C, has been expanding over the circulation. Recent ASCAT-A and ASCAT-B scatterometer passes showed an asymmetric wind field, with peak winds of around 45 kt north of the center. Given these new data and the improving convective presentation, the initial intensity is raised to 45 kt. The initial motion is estimated to be about 280/10 kt. The storm continues to be steered generally west-northwestward to westward south of a low- to mid-level subtropical that should persist through the forecast period. The track guidance remains in good agreement, although the latest guidance has continued to shift slightly northward. The updated NHC track forecast is largely unchanged, blending the previous advisory, the multi-model consensus (HCCA), and the Google DeepMind ensemble mean. Little change in strength is expected during the next 24 h while Norbert remains in a marginal environment tempered by mid-level dry air and some west-southwesterly vertical wind shear. Some fluctuations in intensity are possible during this period as intermittent bursts of deep convection develop near the circulation. Thereafter, increasingly unfavorable conditions will induce a steady weakening trend. The NHC intensity forecast is largely an update of the previous advisory and shows Norbert degenerating into a post-tropical remnant low by 60 h and dissipating as it opens into a trough by 72 h. FORECAST POSITIONS AND MAX WINDS INIT 13/0900Z 18.0N 131.7W 45 KT 50 MPH 12H 13/1800Z 18.3N 133.5W 45 KT 50 MPH 24H 14/0600Z 18.8N 135.8W 45 KT 50 MPH 36H 14/1800Z 19.1N 138.5W 40 KT 45 MPH 48H 15/0600Z 19.4N 141.1W 35 KT 40 MPH 60H 15/1800Z 19.5N 144.0W 30 KT 35 MPH...POST-TROP/REMNT LOW 72H 16/0600Z...DISSIPATED $$ Forecaster Pierce/Gibbs
Tropical Storm Norbert Wind Speed Probabilities Number 15
Issued at 0900 UTC SUN SEP 13 2026 000
FOPZ14 KNHC 130848
PWSEP4
TROPICAL STORM NORBERT WIND SPEED PROBABILITIES NUMBER 15
NWS NATIONAL HURRICANE CENTER MIAMI FL EP142026
0900 UTC SUN SEP 13 2026
AT 0900Z THE CENTER OF TROPICAL STORM NORBERT WAS LOCATED NEAR
LATITUDE 18.0 NORTH...LONGITUDE 131.7 WEST WITH MAXIMUM SUSTAINED
WINDS NEAR 45 KTS...50 MPH...85 KM/H.
Z INDICATES COORDINATED UNIVERSAL TIME (GREENWICH)
PACIFIC DAYLIGHT TIME (PDT)...SUBTRACT 7 HOURS FROM Z TIME
HAWAIIAN STANDARD TIME (HST)...SUBTRACT 10 HOURS FROM Z TIME
WIND SPEED PROBABILITY TABLE FOR SPECIFIC LOCATIONS
CHANCES OF SUSTAINED (1-MINUTE AVERAGE) WIND SPEEDS OF AT LEAST
...34 KT (39 MPH... 63 KM/H)...
...50 KT (58 MPH... 93 KM/H)...
...64 KT (74 MPH...119 KM/H)...
FOR LOCATIONS AND TIME PERIODS DURING THE NEXT 5 DAYS
PROBABILITIES FOR LOCATIONS ARE GIVEN AS OP(CP) WHERE
OP IS THE PROBABILITY OF THE EVENT BEGINNING DURING
AN INDIVIDUAL TIME PERIOD (ONSET PROBABILITY)
(CP) IS THE PROBABILITY OF THE EVENT OCCURRING BETWEEN
06Z SUN AND THE FORECAST HOUR (CUMULATIVE PROBABILITY)
PROBABILITIES ARE GIVEN IN PERCENT
X INDICATES PROBABILITIES LESS THAN 1 PERCENT
PROBABILITIES FOR 34 KT AND 50 KT ARE SHOWN AT A GIVEN LOCATION WHEN
THE 5-DAY CUMULATIVE PROBABILITY IS AT LEAST 3 PERCENT.
PROBABILITIES FOR 34...50...64 KT SHOWN WHEN THE 5-DAY
64-KT CUMULATIVE PROBABILITY IS AT LEAST 1 PERCENT.
- - - - WIND SPEED PROBABILITIES FOR SELECTED LOCATIONS - - - -
FROM FROM FROM FROM FROM FROM FROM
TIME 06Z SUN 18Z SUN 06Z MON 18Z MON 06Z TUE 06Z WED 06Z THU
PERIODS TO TO TO TO TO TO TO
18Z SUN 06Z MON 18Z MON 06Z TUE 06Z WED 06Z THU 06Z FRI
FORECAST HOUR (12) (24) (36) (48) (72) (96) (120)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
LOCATION KT
20N 135W 34 3 21(24) X(24) X(24) X(24) X(24) X(24)
20N 140W 34 X X( X) 8( 8) 18(26) 1(27) X(27) X(27)
20N 140W 50 X X( X) X( X) 4( 4) X( 4) X( 4) X( 4)
20N 145W 34 X X( X) X( X) X( X) 10(10) X(10) X(10)
$$
FORECASTER PIERCE/GIBBS
Tropical Storm Norbert Graphics
Wind Speed Probabilities last updated Sun, 13 Sep 2026 09:22:58 GMT