697
WTPZ44 KNHC 010836
TCDEP4
TROPICAL DEPRESSION FOUR-E DISCUSSION NUMBER 1
NWS NATIONAL HURRICANE CENTER MIAMI FL EP042026
200 AM PDT WED JUL 01 2026
THE AREA OF LOW PRESSURE (95E) OVER THE WESTERN EAST PACIFIC HAS
CONTINUED TO BECOME BETTER ORGANIZED OVER THE LAST 12 HOURS.
PERSISTENT DEEP CONVECTION HAS DEVELOPED PRIMARILY OVER THE EASTERN
AND SOUTHERN PORTIONS OF THE CIRCULATION, WITH CURVED BANDING
FEATURES BECOMING WELL DEFINED. RECENT SCATTEROMETER DATA
INDICATE THAT THE SYSTEM HAS DEVELOPED A CLOSED, ALTHOUGH SOMEWHAT
ELONGATED, LOW-LEVEL CIRCULATION WITH MAXIMUM WINDS AROUND 30 KT.
SUBJECTIVE DVORAK CURRENT INTENSITY ESTIMATES HAVE INCREASED TO T1.5
FROM TAFB. BASED ON THESE DEVELOPMENTS, THE SYSTEM HAS BEEN
DESIGNATED AS TROPICAL DEPRESSION FOUR-E, WITH AN INITIAL INTENSITY
OF 30 KT.
THE DEPRESSION IS MOVING NORTH-NORTHWESTWARD (345/6 KT), AND THIS
GENERAL MOTION IS FORECAST TO CONTINUE OVER THE NEXT COUPLE OF DAYS
ALONG THE WESTERN PERIPHERY OF A RIDGE OVER THE CENTRAL PORTION OF
THE EASTERN PACIFIC BASIN. MODELS ARE IN FAIRLY GOOD AGREEMENT WITH
THIS GENERAL MOTION, AND THE OFFICIAL NHC FORECAST LIES NEAR THE
SIMPLE AND CORRECTED-CONSENSUS AIDS. TOWARDS THE END OF THE PERIOD,
AS THE SYSTEM WEAKENS AND TURNS WESTWARD INTO THE LOW-LEVEL FLOW,
THERE IS SLIGHT TIMING DIFFERENCES OF WHEN THAT OCCURS BASED ON THE
CONVECTIVE STRUCTURE. THE NHC FORECAST CONTINUES TO LIE NEAR OR
JUST TO THE LEFT OF THE CONSENSUS AIDS TOWARDS THE END OF THE
PERIOD.
THE SYSTEM HAS ABOUT A DAY OR SO TO STRENGTHEN WITHIN A FAVORABLE
LOW-SHEAR, MOIST ENVIRONMENT, SUPPORTED BY UPPER-LEVEL DIVERGENCE.
THE OFFICIAL FORECAST HAS THE SYSTEM STRENGTHENING INTO A TROPICAL
STORM LATER TODAY, WHICH IS GOOD AGREEMENT WITH THE LATEST INTENSITY
AIDS. HOWEVER, AS THE SYSTEM MOVES NORTH-NORTHWESTWARD, IT WILL
ENCOUNTER COOLER SSTS ALONG ITS TRACK. IN ABOUT 36–48 HOURS, WIND
SHEAR IS FORECAST TO INCREASE, AND THE SYSTEM WILL MOVE INTO A DRIER
MID-LEVEL AIRMASS. GIVEN THE COMBINATION OF COOLER SSTS AND THE
INCREASINGLY UNFAVORABLE ENVIRONMENT, THE SYSTEM IS FORECAST TO
WEAKEN AND WILL EVENTUALLY STRUGGLE TO SUSTAIN DEEP CONVECTION.
SIMULATED IR IMAGERY FROM THE GFS AND ECMWF SUGGESTS THE SYSTEM
COULD BECOME DEVOID OF DEEP CONVECTION BY AROUND 60 HOURS. THUS, THE
NHC FORECAST CALLS FOR THE SYSTEM TO WEAKEN INTO A POST-TROPICAL
REMNANT LOW AT THAT TIME, AND DISSIPATING INTO AN OPEN TROUGH BY
THE END OF THE FORECAST PERIOD.
FORECAST POSITIONS AND MAX WINDS
INIT 01/0900Z 14.5N 126.9W 30 KT 35 MPH
12H 01/1800Z 15.2N 127.0W 35 KT 40 MPH
24H 02/0600Z 16.3N 127.1W 35 KT 40 MPH
36H 02/1800Z 17.4N 127.3W 35 KT 40 MPH
48H 03/0600Z 18.4N 127.8W 30 KT 35 MPH
60H 03/1800Z 19.2N 128.6W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 04/0600Z 19.7N 129.6W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 05/0600Z 20.3N 132.4W 20 KT 25 MPH...POST-TROP/REMNT LOW
120H 06/0600Z...DISSIPATED
FORECASTER KELLY
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