FXUS64 KBRO 061741

AFDBRO



Area Forecast Discussion

National Weather Service Brownsville TX

1241 PM CDT Wed May 6 2026



...New DISCUSSION, AVIATION, MARINE...



.KEY MESSAGES...

Updated at 1237 PM CDT Wed May 6 2026



Key Messages:



 * Heat Advisories are in effect into this evening for most of the

   Rio Grande Valley. 



 * The chance of rainfall, heavy at times, returns Thursday

   through Friday across Deep South Texas with a Marginal (level 2

   of 4) Risk of Excessive Rainfall. 



 * There is a low but non-zero chance for strong to severe

   thunderstorms near the brush country late tonight through

   Thursday morning and across the Rio Grande Valley Thursday

   afternoon into Thursday night. 



&&



.DISCUSSION...

Issued at 1237 PM CDT Wed May 6 2026



A Baja mid-level low barrels east into Texas by the weekend 

before ejecting northeast into early next week. At the surface, a 

frontal boundary is currently heading south through Central Texas,

and was expected to somewhat stall near Deep South Texas on 

Thursday, meander around the area on Friday, and gradually edge 

offshore by Saturday. NBM has not handled the front well so far, 

and may be slow and too warm at this time. Have collaborated with 

northern offices to mix CONSHORT and BCCONSHORT into guidance, 

speeding up and cooling down the frontal passage a little. 



PWAT values build above 2 inches across the brush country and 

across the border late tonight into early Thursday before working 

east across the remainder of Deep South Texas, potentially 

reaching 2.2 inches by Thursday night. The 90th percentile for 

early to mid March is around 1.75 inches, meaning this is an 

abnormally moist atmosphere for this time of year and any showers 

or thunderstorms will be very efficient rainmakers. WPC has placed

a Marginal (level 1 of 4) Risk for Excessive Rainfall across 

Zapata, Starr, southeastern Jim Hogg, and western Hidalgo counties

for Thursday, and the entire CWA on Friday. Guidance has 

generally centered towards late Thursday afternoon through mid 

Friday morning from west to east, with a small subset of CAMs 

firing convection late tonight just across the border from Zapata 

and gradually working it south and east through Thursday evening, 

a period quicker than NBM. With little steering flow, any activity

may also be slow-moving, playing into the heavy rain threat. 

Early rainfall estimates are around 1-2 inches, with locally 

higher amounts of 3-4 inches where any showers or thunderstorms 

persist. 



There is a low but non-zero chance of severe thunderstorms along

and ahead of the frontal boundary late tonight west of Zapata and

Thursday afternoon into Thursday night across the upper to mid

RGV. Damaging winds, large hail, and flooding rainfall would be

the main concerns at this time. Generally drier conditions are

expected through the remainder of the forecast period, with above

normal temperatures over the weekend and another front on Monday

dropping temperatures back towards normal through early next week.

Heat risk remains Moderate (level 2 of 4) through the weekend. 



&&



.AVIATION...

(18Z TAFS)

Issued at 1237 PM CDT Wed May 6 2026



MVFR conditions have held on a bit into this afternoon. A brief

VFR break is expected mid to late afternoon into this evening

before MVFR ceilings return. There is a chance of severe

thunderstorms west of the RGV late tonight, generally across the

border, with tall CB and potential hail. A frontal boundary is

expected to shift winds northeasterly after daybreak Thursday.



&&



.MARINE...

Issued at 1237 PM CDT Wed May 6 2026



A frontal boundary sags south into Thursday with brief northerly

flow, meandering around the lower Texas coast through Friday,

before lifting north over the weekend. The next front arrives on

Monday with brief northerly flow, before southeasterly winds

return Tuesday. Outside of seas building briefly behind each front

or with any thunderstorms Thursday through Friday night, marine

conditions are expected to be generally favorable. 



&&



.PRELIMINARY POINT TEMPS/POPS...

BROWNSVILLE             79  86  78  90 /   0  20  40  30 

HARLINGEN               77  83  75  91 /   0  30  50  40 

MCALLEN                 78  84  75  92 /  10  40  60  40 

RIO GRANDE CITY         77  85  73  90 /  10  40  60  30 

SOUTH PADRE ISLAND      78  80  78  84 /   0  20  40  30 

BAYVIEW/PORT ISABEL     78  82  77  89 /   0  20  50  30 



&&



.BRO WATCHES/WARNINGS/ADVISORIES...

TX...Heat Advisory until 7 PM CDT this evening for TXZ251-253>255.



GM...None.

&&



$$



SHORT TERM...56-Hallman

LONG TERM....56-Hallman

AVIATION...56-Hallman