July: Hot & Humid To End The Month

[srainhoutx]

The 13Z HRRR is rather suggestive of some stronger storms across our eastern zones as this disturbance moves generally W bound throughout the day.

[srainhoutx]

Morning e-mail from Jeff:

Large dome of high pressure located over N TX and OK with extreme heat will remain in place for much of this week.

Upper air analysis shows an expansive ridge of high pressure centered over the TX panhandle into SE CO this morning with SE TX sitting on the SE flank of this feature. Upper level steering flow over our region is out of the ENE so our weather will be driven over the next 3-5 days by any weak disturbances rounding the eastern side of this ridge and crossing near/south of our area. This suggest that any small rain chances will be focused near the coast/offshore through at least Thursday with ridging in place across the rest of the area. One such disturbance moved across the coastal waters yesterday producing a few storms south of I-10 during the afternoon hours. While it will be hot with the ridge near, it will not be the brutal heat that will bake much of the central plains this week. High temperatures will top out in the mid to upper 90’s during the afternoon hours, but a weak landbreeze overnight will allow morning lows to fall into the mid 70’s at most locations. Overall fairly normal weather for late July.

Toward the end of the week, the ridge over the plains will retrograde westward and yet another weakness in the height field aloft develops over LA and E TX (so common this summer). Will need to bring rain chances back into the forecast starting Saturday. Sunday looks to possibly see some fairly decent coverage with deeper moisture advecting into the area and ridging backing to the west. It should be noted that this pattern places the Gulf coast at the mercy of any possible tropical waves/systems in the Atlantic hurricane pipeline with little to no blocking ridging for protection.



Tropics:

99L:
An area of low pressure has developed 800 miles SW of the Cape Verde Islands. This system is moving westward at 10-15mph with scattered thunderstorms. Global forecast models all suggest some degree of development with this system with the CMC being the most aggressive. Conditions across the middle of the deep tropical Atlantic appear favorable for slow development. While most of the models do show some development, most cap the system near tropical storm intensity. With deep layer high pressure north of 99L over the central Atlantic, the westward motion should continue for the next several days.

[srainhoutx]

Afternoon e-mail from Jeff re: Comparing July 2011 to July 2012:

All,

I have compared the rainfall cross Harris County for July 2011 and July 2012 and the results are very impressive (showing how dry 2011 was and how wet 2012 has been).

Over the northwest part of the county, where rainfall was least last July it has been the greatest this July. Most locations across Harris County are running over 5 times the amount of rainfall this July compared to last July and across the NW part of the county the rainfall this July is 10-15 times more. For a dramatic comparison site 1190 (Little Mound Creek at Mathis Road:July 2011: .04 in compared to July 2012: 17.52 in)

I have also attached all the Flood Warning gage stations for July 2012 and July 2011 rainfall at each site and the differences along with a graph showing the difference. I also attached the January to July rainfall and those differences.

July 2012 Rainfall:

July 2011 Rainfall: