The abnormally quiet severe weather season has really picked up once again with the most active day since April. Powerful storms from yesterday and merged overnight into a large, long lasting complex of severe thunderstorms, known as a Mesoscale Convection Complex. These large systems which can span hundreds of miles is bringing damaging wind and large hail and flash flooding with perhaps the odd tornado.

While still volatile today, the low level jet supporting this intense situation into this morning will weaken some but there’s still a serious threat into the Ohio/Tennessee Valley today into tonight.

Check out this infrared imagery showing the MCS currently crossing the cornbelt.

Closer look at this beast.

Check out this amazing structure and high echo chart from the severe thunderstorm which hit Omaha, NE hard last night. Via Stu Ostro.

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According to AccuWeather, 5.13 inches of rain fell within 8 hours in Omaha, NE producing flash flooding.

Often with severe storms, you get ‘heat bursts’. There was an impressive one over Kansas late last night.

In 35 mins, the temp rose from 85 to 93 between 10 and 10.35pm in Russell, KS. Produced by collapsing thunderstorms.

Salina, KS has reportedly climbed from 84 to 95F within one hour overnight.

Latest 500mb height chart off GFS

Surface

Here’s the SPC risk area for today.

Major cities at greatest risk.

A lot of focus in recent times has been the heavy and widespread rainfall and sure enough, the QPF still shows major rains over the heart of the nation but notice the coverage of 1-3″ amounts.

Should be no surprise that heat will be confined largely to the West and South.

As for the tropics, while the US is not affected (just yet), we’re watching Tropical Storm Boris as it comes ashore along the SW Mexico coast.

Here’s the latest infrared imagery. Note the large ball of deep convection that’s now onshore with the core of circulation just off the coast.

Boris will take time to cross southern Mexico and because of that, it won’t strengthen and it will present a life-threatening flash flood situation.

The NHC continues to watch the Bay of Campeche for weak development as Boris perhaps crosses into the Atlantic basin or a new low forms. This, if happens is likely to be a slow process.

In saying that, notice the convection blowing up on the Atlantic side of Mexico.

Note from the NHC.

1. A stationary trough of low pressure over the Bay of Campeche is
producing cloudiness and disorganized showers. Strong upper-level
winds are expected to limit significant development during the next
few days while the system moves little.  Regardless of development,
locally heavy rainfall is possible over portions of southeastern
Mexico, including the Yucatan Peninsula, during the next few
days.
* Formation chance through 48 hours…low…10 percent
* Formation chance through 5 days…low…20 percent

Track of Boris.

At least a foot of rain may fall over far southern Mexico/central America from Boris which will likely lead to flash flooding and mudslides.

QPF rainfall over Mexico next 7-days.

A reminder as to just how ‘fortunate’ and overdue the US is for a ‘major’ hurricane.

NO Heatwave In Sight!

Looking cool up till at least mid-month according to the GFS ensembles.

2-8 day

9-15 day

Really with the exceptions of the S Plains into the Mid-South, perhaps Southeast, the emphasis is largely on COOL through this month.

Video will be available later! Stay tuned.

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