SPC MD 1330

MD 1330 CONCERNING SEVERE POTENTIAL…WATCH LIKELY FOR THE FRONT RANGE OF CO AND FAR SOUTHEAST WY


Mesoscale Discussion 1330
NWS Storm Prediction Center Norman OK
1108 AM CDT Tue Jun 17 2025

Areas affected...the Front Range of CO and far southeast WY

Concerning...Severe potential...Watch likely 

Valid 171608Z - 171815Z

Probability of Watch Issuance...80 percent

SUMMARY...Initially isolated storms along I-70 in east-central
Colorado will pose a risk for severe hail. More widespread storms
are expected to form along the Front Range by early afternoon with a
primary threat of large to very large hail. A watch issuance is
likely, with some uncertainty on timing.

DISCUSSION...Convection has formed early atop the pervasive stratus
deck across east-central/southeast CO, with more pronounced
insolation in a confined wedge to its north across northeast CO.
While the boundary layer is cool and still somewhat stable, a risk
for severe hail may develop with this localized area of storms given
sufficient deep-layer shear. 

The pervasive stratus is indicative of the seasonably moist air mass
banked against the southern Rockies. Forecast soundings suggest only
modest boundary-layer heating is needed for uncapped parcels, with
most 12Z guidance indicative of scattered to widespread storms along
the Front Range by early afternoon. With weak low-level shear,
overall setup should be favorable for large to very large hail
potential across the I-25 corridor. Very large hail appears more
probable across the southern portion of the region where effective
bulk shear should be maximized across the COS/PUB vicinity.

..Grams/Hart.. 06/17/2025

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...GLD...PUB...BOU...CYS...

LAT...LON   39430310 38730310 37550395 37760487 38340517 38870522
            39940524 40360532 40660536 41110529 41710484 41760447
            41670416 41030400 39430310 

MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN

StormPrep