The Heat Begins

Yesterday we received another drencher of .03 of an inch (just a joke).  Allegan County remains relatively dry with only 1.66 inches for the month and 2.5 inches for the summer.  Otsego is about three miles west of US 131 and most of the cells and storms have formed just east of that.

We will begin our ascent into an airmass with warmer and more humid air with temperatures rising into the low to mid 80s with chances of storms once again east of US 131.

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U.S.A and Global Events for July 24th:

1930: An estimated, F5 tornado tore through Montello, Veneto, and Friuli in Italy. The tornado killed 23 people along its 50-mile path.

1952: The temperature at Louisville, Georgia soared to 112 degrees to establish a state record. The temperature also hit 112 degrees in Greenville, Georgia on August 20, 1983.

2008: A tornado fluctuated between the category EF1 and the more destructive EF2 strikes Northwood and Pittsfield, as well as nine other towns in New Hampshire. It first touches down in Deerfield, then travels through Northwood, Epsom, Pittsfield, Barnstead, and Alton. From there, it rages through New Durham, Wolfeboro, Freedom, Ossipee, and Effingham. The storm destroyed several homes, damaged dozens of others, and killed at least one person.

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Grand Rapids Forecast

[pdf-embedder url=”https://michigan-weather-center.org/wp-content/uploads/2023/07/7-24-grr.pdf” title=”7 24 grr”]

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Forecast Discussion

- A Few Showers and Thunderstorms Again Today into Tuesday

Upper troughing continues today but we will not have as robust of
a 500 mb wave moving through the region. Nevertheless, similar
PWATs (1.25") will be in place today as a lake breeze once again
develops and will help serve as a mesoscale focus for lift. HREF
mean SBCAPE values of 1000-1500 J/kg are indicated today. The high
res CAMs are not bullish on precipitation coverage and intensity
today, and as such the HREF probability matched mean QPF values
for 3/6/24 hrs are very low. Still, 4 hr max reflectivity values
suggest the favored area for isolated to scattered showers and
thunderstorms will be along and east of US 131.

While not currently in the forecast, some late night showers may
impact areas north of M-46, which could also spill over into early
Tuesday morning. HREF 4 hr max reflectivity neighborhood
probability of 40 dBZ or greater with at least some MUCAPE does
show 10%-30% in the aforementioned region during those time
frames. So, precipitation may be introduced if the models trend in
that direction further.

Rain chances on Tuesday do not look great with mid level height
rises occurring during the day and less surface based instability
present, but 0-6 km shear could be around 30 kts which is better
than Monday and also PWATs look to be around 1.25" again, so
maintaining mention for a few showers and thunderstorms near and
east of US 131 is warranted.

.LONG TERM...(Tuesday night through Sunday)
Issued at 329 AM EDT Mon Jul 24 2023

Quasi zonal flow aloft will lead to a couple of opportunities for
showers and thunderstorms during the period.

Both the GFS and ECMWF show a compact short wave moving across
northern IL Wednesday and develop convection in response. Bulk shear
values climb to around 30 knots during the afternoon which in
combination with a strengthening LLJ could lead to a few stronger
storms south of I-96. Once the wave moves by Wednesday night, PoPs
will decrease.

Thursday night and Friday may be another opportunity for rain. A
wave moving across the U.P is progd to push a cold front south
across Lower MI but the models differ in their timing. However, both
develop a wave on the front and move that wave across the cwa in the
Thursday night - Friday night time frame. We`ll keep the chance PoPs
going for this.

The GFS is more aggressive with pushing the front south of the cwa
versus the ECMWF. As a result, the GFS builds a high in quickly for
the weekend. However, the ECMWF is slower pushing the front through
and develops yet another wave on the front and moves it through
Saturday. So, the GFS is dry and the ECMWF is wet Saturday. We`ll
continue with low chc PoPs as a nod to the uncertainty.

The ECMWF finally pushes the front south by Sunday and builds in the
high like the GFS did the day before. Basically, the GFS is 12-18
hrs quicker than the ECMWF.

This week will be hot and humid...pretty typical for late July in
Michigan. Highs will climb to around 90...many spots climbing above
90...and dewpoints will climb to around 70 by mid week.