Summaries and Storm Chances

Yesterday we reached a temperature of a very nice 76° with a few clouds from time to time.

High temperatures will be frequently in the 70s over the next week although it will be cooler at times near Lake Michigan. Showers and thunderstorms are a good bet on Friday as a frontal system comes through, otherwise only low chances of a shower exist through the weekend.

April Summary

Winter Summary

SPC Day One Outlook

NWS Forecast

Weather History

1929: A snowstorm puts down a slushy coating of 2 to 3 inches of snow across southwest Lower Michigan.

1930: Grand Rapids was struck by a tornado that moved through the factory district in the southern part of the city. Four people were injured and many buildings were unroofed. Damage totaled over a million dollars.

On May 2, 2015, this day in geologic history featured a 4.2M earthquake that was felt in several states. The epicenter was 5 miles south of the town of Galesburg in Southwest Lower Michigan. It was the 2nd strongest earthquake on record in Michigan behind a 4.6M near Kalamazoo in 1947.

On May 2, 1983, an F2 tornado hit Lenawee County between 1:35 a.m. and 1:40 a.m. Later that same morning, an F3 tornado hit Macomb County at 10:05 a.m. causing $25 million in property damage.

1762: A tornado struck Port Royal Island, South Carolina. It left a path 400 yards wide, tore up trees by the roots, and carried away houses and bridges.

1929: Virginia’s worst tornado disaster occurred on this day. Six tornadoes, two of which were west of the Blue Ridge Mountains, killed 22 people. One tornado killed twelve children and a teacher at Rye Cove, in Scott County. The storms destroyed four schools.

1983: Severe thunderstorms produced 21 tornadoes across the northeastern states of Michigan, Ohio, Pennsylvania, and New York. One tornado even occurred in Ontario, Canada. Of the 21 tornadoes in the United States, nine were rated F3, and six were rated F2. The tornadoes caused five deaths.

2010: May began with two days of historical rainfall over much of Middle Tennessee, with a massive swath stretching along the I-40 corridor from Benton County to Davidson County. Some areas received nearly 20 inches of rain during this 2-day period, the highest of which was 19.41 inches reported by a CoCoRaHS observer in Camden, TN. Numerous rainfall records were broken at the Nashville International Airport, including the most rain received in a 6-hour period, the highest calendar day rainfall, and the wettest month, along with several others. Incredibly, the Nashville Airport experienced its wettest and third wettest days in history on back-to-back days. Many area rivers exceeded their record crest levels, including the Harpeth River near Kingston Springs, which rose to 13.8 feet above the previous record. The Cumberland River at Nashville reached its highest level since flood control was implemented in the late 1960s, flooding parts of downtown Nashville. Waters from the Cumberland reached as far inland as 2nd Avenue, flooding many downtown businesses. Forty-nine Tennessee counties were declared disaster areas with damage estimates of between $2 and $3 billion statewide. Many Nashville landmarks received damage from floodwaters, including the Gaylord Opryland Hotel and the Grand Ole Opry. Other popular Nashville landmarks affected by the floods include LP Field, Bridgestone Arena, the Country Music Hall of Fame, and the Schermerhorn Symphony Center, which received damage to the basement and its contents, including two Steinway grand pianos and the console of the Martin Foundation Concert Organ. Over $300 million in Federal Disaster Assistance was approved for the people of Tennessee.

Forecast Discussion

- Chance for thunderstorms later today into Friday

The first half of the day today should continue where Wednesday left
off with mild temperatures and some cloud cover in place. We will
see some smaller rain chances start to develop after noon for areas
further North and West. The reason this is the case is that the low
level jet that will be driving this round of showers and storms will
be focused much more to our NW. In addition, the lower level
moisture is lacking here, with a good deal of mid clouds moving
through. This is likely to result in a few sprinkles/light showers
falling from a mid cloud deck.

The best chance for rain will come later this evening and last
through Friday morning before starting to push east of the forecast
area. This is when the last part of the low level jet is exiting the
area, and moisture pooling ahead of the sfc front will be sufficient
for rain to be likely.

Thunder chances start to move over the area this afternoon, once
again further NW, closer to the low level jet and the better
moisture and warmth aloft. Some of the convection allowing models
are trying to bring MU CAPEs up into the 1500 J/kg toward midnight
tonight, supporting a thunder mention. The amount of instability is
likely what the Marginal Risk from the SPC is focused on. It is a
pretty healthy amount of instability present.

The limiting factors that will keep the storms likely on the more
tame side is due to the upper wave staying well west of the area.
This track will also take the core of the low level jet further
west. The entire system will take its time to move through the
entire area with the front almost nearly parallel to the upper flow.

- Warm and Mostly Dry Weekend

A secondary weak sfc cold front is shown to slowly drift in from the
west over the weekend as the nrn Plains upper low/trough moves to
Hudson Bay. Only 20-30 pct pops are in the forecast ahead of this
feature however due to lack of stronger forcing, and the bulk of the
weekend should be dry with warm temperatures in the 70s.

A weak sfc high and drier air mass builds in behind that front for
Sunday night into Monday and the baroclinic zone temporarily settles
just south of MI. Also an upper ridge builds overhead during this
time as next upper low/trough moves into the nrn Plains, suggesting
a dry day. However the warm front returns north again on Monday
night which brings a renewed chance of showers and storms.

- Showers and Storms Tuesday/Tuesday Night

A potentially active period is Tuesday afternoon and evening as a
shortwave heads northeast from KS and sends a front in our
direction. Moisture return from the Gulf via 40 kt low level jet
should result in numerous showers and storms developing and will
carry 60-70 pct pops. Fcst confidence in convective potential
decreases by the middle of next week with large ensemble QPF/timing
spread noted, but temps look to remain above normal.