Winter 2002-2003 Review

The Winter of 2002-03 will be well remembered as endurably cold and long lasting over Southeast Lower Michigan. The Winter of 2002-03 was the coldest winter over the region since the Winter of 1993-94.While the Winter of 1993-94 was a bit colder than this past winter, it generally was nowhere near as snowy. The Winter of 1993-94, however, was neither an El Niño nor a La Niña Winter, but a Neutral Winter (for more on neutral winter effects in Southeast Lower Michigan, see the 2001-2002 winter outlook). While the past overall winter was cold, the average temperature of 24.1 degrees in Detroit did not place in Detroit's top 20 coldest winters on record. However, with average temperature of 22.5 degrees at Flint, this past winter did make Flint's coldest winters list /15th/ and likewise, so did the average temperature of 21.3 degrees at Saginaw /19th/. In regards to Detroit, it should be noted that this past winter's average temperature of 24.1 degrees ranked 0.7 of a degree warmer than the 20th place /23.4 degrees/ for coldest winters (1871-72 and 1894-95).

One of more notable items about this past winter cold was it's endurance and staying power. As the winter evolved, it was became more and more difficult to have a stretch of above normal temperatures. While temperatures generally started out around normal in the month of December across Southeast Lower Michigan, it was pretty much all downhill from there as cold weather basically dominated into mid March (then returning for a visit early April). This was primarily a result of the persistent strong northwesterly flow that prevailed since mid October. While the cold was not exceptionally severe, it still did have exceptional staying power even for January and February, which normally contain the bulk of our cold winter weather anyway.

While snowfall was frequent and plentiful across the majority of Southeast Lower Michigan, there were notable exceptions in portions of the Saginaw Valley and Northern Thumb Region, where nearly persistent drier weather held the snowfall totals down. The range of snowfall totals were still quite exceptional for the relatively small region, considering most areas received synoptic snowfall (as opposed to Lake effect snow where totals can vary considerably in just a short distance). In addition, the higher amounts fell in the normally lower seasonal snowfall region...that is, extreme Southeast Lower Michigan (from the Metro Detroit area south to Ohio).

As little as 25 to 30" of snow was reported near the Saginaw Bay (see snowfall chart) to as much as 65 to 70" in the southern third of the region from around Detroit to the Ohio border. The wide-range of snowfall totals represented well the nearly exclusive southern jetstream storm track into the Ohio Valley, as evidenced by the well above normal snowfall totals over extreme Southeast Lower Michigan.

Chronologically Speaking:

DECEMBER:

Temperatures actually averaged out around normal across Southeast Lower Michigan for the first winter month of December. During the first week of the month, however, a very deep upper level trough pushed arctic air into the region after the area experienced its first snowstorm. Nearly six inches of snow fell at Detroit on the 2nd with lesser amounts further north around Flint and Saginaw. A significant lake effect snow band formed with higher snowfall totals downwind of Lake Huron over Sanilac and St Clair counties. In Port Huron, snowfall totals of up to nearly nine inches were reported. This was the second Lake Effect snow over the downwind communities of the lake. Winter actually got a jump start over this area in November when a rather early lake effect snowfall took place on November 26-27th and dropped snowfalls of 12 - 18" in a narrow band.

The first cold snap of the December held sway over the region until mid month. The average temperature during the first week of December was only around 20 degrees...or about 13 degrees below normal! A mid month warm up boosted temperatures back up to normal or above normals levels. The second half of the month was considerably milder than the first half with the monthly average temperature warming back up into upper 20s over Southeast Lower Michigan. Besides the early month snow and cold, the other most notable December event was our Christmas snowstorm. A deepening low pressure system moved through the Ohio Valley Christmas Eve into Christmas Day and provided Southeast Lower Michigan with a picturesque white Christmas. Snowfall totals generally ranged from two to six inches across the Saginaw Valley and Thumb Regions and south into Flint and Port Huron, while four to seven inches prevailed across the Metro Detroit/Ann Arbor areas south to the Ohio border. Monthly temperatures generally averaged within a degree of normal, while snowfall ranged from below normal at Saginaw to above normal at Flint, the NWS in White Lake, and Detroit.

JANUARY:

January lived up to it's cold reputation with temperatures in all areas in Southeast Lower Michigan averaging distinctly below normal! Since January is normally our coldest month, the significantly below normal readings were especially noteworthy. Like in early December, another snowstorm took aim on Southeast Lower Michigan in early January, mainly around the Metro Detroit area south to Ohio. A very brief warm-up late on the 8th into early on the 9th was soon history as another Arctic front heralded in a strong shift in the jetstream back to the northwest (like early December) which brought in much colder weather to the region. In fact, a strong and persistent deep cold upper trough planted itself over the Great Lakes from the 10th right through the remainder of the month. This cold trough was well reflected by the persistently below normal temperatures seen during that time. The weather also turned more mundane during the remainder of January with persistent cold and occasional light snows. Snowfall from Flint northward into the Saginaw Valley and Thumb Region, however, continued to track below normal and was reflected in deficits in both snowfall and precipitation. The temperature fell to -2 on the 27th in Detroit and this was the first time a below zero reading had been registered since December 23rd, 2000, when it fell to -1. The temperature fell to -11 also on the 27th at Flint and this tied the old record low set first back in 1943. The last time the temperature was as cold or colder in Flint was back on Christmas of 2000 when the mercury fell to -13 degrees.

FEBRUARY:

During February, the winter weather for the most part, actually worsened with an increase in the number of substantial snowfalls as temperatures continued to average below normal. Detroit's February snowfall total blossomed to 19.2 inches which was nearly 10 inches /9.9/ above the norm. Flint also saw an increase in monthly snowfall with 12.5 inches /+3.1/, while Saginaw remained the only below normal hold out with just 7.2 /-1.1/. February's temperature pattern was similar to January's. In the midst of a nearly continuous string of cold days, very brief and relatively "balmy" periods surfaced each month. Two of these three warmer surges in January and February were caused by a strong storm center passing to our west, bringing up very quick shots of mild air. It first happened late Jan 8th into early the 9th, then again late on Feb 3rd into early the 4th. Since both of these warm-ups came in mainly overnight, the public was less aware of them. Afterwards, just two other nice 40+ degree days occurred in February /20th-21st/. Therefore, with only six 40+ degree days January through February, that left about 90 percent of the time that the temperature held below 40. In addition, during those two months, high temperatures were 32 degrees or lower on 45 days (but these were not in a continuous streak). About 76 percent of the time in January through February, the temperature held at freezing or below! The record for a continuous streak of high temperatures 32 degrees or lower happened during the very cold winter of 1976-77 (ave temp 19.8) and that was also 45 days - in a row!

MARCH:

It was one cold, angry lion that greeted Southeast Lower Michigan residents during the first half of March. The first ten days saw some of the coldest weather ever seen in early March with temperature averages ranging from around 16 to near 21, or some 12 to 15 degrees below the normal. Curiosity about the strength of the cold led to a check of the top 5 coldest Marchs on record at Detroit (largest data base to 1870) and their comparative temperature trends to this past early-mid March time period. While we did not experience the worst historical cold in early to mid March, we certainly were in the ballpark. Most of these top five coldest Marchs also had the coldest of weather early or mid March.

Top coldest (Detroit)
Marchs.............March 1-10th.........March 1-15th
Normal                  33.1                       34.0
---------------------------------------------------------
1- 1872                  19.7                       22.5 
2- 1877                  24.6                       24.4   
3- 1960                  17.0                       18.0
4- 1900                  25.2                       23.8
5- 1885                  27.2                       26.8
---------------------------------------------------------
    2003                  21.2                       24.6

Since these are just the top five coldest March (and just the early to mid March time frame), there would be likely some other Marchs in the group and not necessarily even from the top 20 coldest Marchs (as evidenced by this March). It does, however, give a good estimate of the intensity of the cold we experienced, especially the first 10 days of March. By far, the most impressive of the six is March of 1960, where the first half of the month averaged just 18 degrees (or nearly HALF the normal of 34)!

The second half of March 2003 moderated considerably across the region with temperatures averaging around normal to well above. Not surprising, the month of March saw both record lows and highs with the extremes seen during the month from near -10 to around 70 above! Ironically, and undoubtably the strangest coincidence between this winter and last winter, especially seeing they were the inverse of one another, was that both of their coldest mornings occurred during the meteorological spring month of March...and almost to the same date! At Detroit, the coldest temperature of this season was -4 on the 3rd, while the coldest temperature last season (2002) was 8 degrees on March 4th! In Flint, however, while a -11 on March 3rd was the coldest of the season (it actually tied with an -11 on January 27th), last season the coldest temperature was +1 on February 5th. However, at Saginaw (like Detroit), the coldest of this season occurred on March 3rd with a -7 and last season's lowest temperature of +1 also occurred on March 4th.

The busy winter storm track of the winter carried right over into March (and April for that matter) while shifting from the mainly the Ohio Valley, a bit northward into the Northern Ohio Valley and Great Lakes with the change of seasons. Several lows tracked north from the Southern Plains or Texas/Arkansas area, northeast into the Great Lakes. Snowfalls across Southeast Michigan were at or above normal for March in most areas with nearly all of it occurring the first half. The largest snowstorm to affect the area in March moved through late on the 4th into the 5th. The snowstorm blanketed the region with snowfalls from near four inches in the Ann Arbor and Detroit area, to as much as eight inches in Northern Oakland and Western St Clair counties. Nearly six inches /5.7/ fell at the NWS office at White Lake. Lesser amounts of an inch or two fell further south near the Ohio border. The snow was the product of what seemed like an endless parade of Ohio Valley low pressure systems this past winter.

APRIL:

The long, cold Winter of 2002-03 was not going to give up easily as that cold, angry lion decided to make another unwelcome visit as March ended and then again, during the first week of April. Mother nature really pulled an April's fool joke on the inhabitants of Southeast Lower Michigan. April 1st was nice enough with sunny skies and high temperatures surging up into the lower to mid 70s as Mother Nature tried to fool area residents into a false sense of security that spring was finally here to stay. The April fools joke came later on April 3rd, when things (especially temperatures) went down hill fast. A strong Arctic front pushed its way south across Southeast Lower Michigan during the afternoon on the 3rd. The temperature extremes across just Southeast Lower Michigan were quite dramatic and impressive with a winter-like airmass contrasting with a summer-like one. While lower to mid 30s were commonplace across the Saginaw Valley and Thumb region, temperatures at the same time were into the 70s (with one or two places even flirting with 80) in Lenawee and Monroe counties. As the front sank south into the Northern Ohio Valley on the 4th-5th, a storm center moved northeast along it and produced thunderstorms, very heavy rain, a dangerous coating of freezing rain - which led to significant icing of 1/4" to near 1" over areas north of a Ann Arbor - Detroit line. By far, the worst of the storm was felt over Oakland county with the heavy ice accumulations of up to an inch in some areas. Customers who lost power totaled up close to a half-million or more across Southeast lower Michigan.

Mother Nature gave us the one-two punch during that first week of April. Yet another storm moved up the Ohio Valley from Eastern Texas on the 7th and dumped generally 3 - 6 inches of snow over extreme Southeast Lower Michigan with lesser amounts further north. This snow made this month the 10th snowiest April on record at Detroit, the 17th snowiest at Flint and 14th snowiest April at Saginaw.

By the 10th (and just like the months of December and March), temperatures across Southeast Lower Michigan averaged 6 to 12 degrees below normal. So intense was the cold for early April that the soil temperature here at the NWS in White Lake, rather than rising with the oncoming spring, FELL from 46 degrees on April 2rd to 32 by the 6th and pretty much remained there until early on the 10th! And, while on the subject of soil temperatures, the official record of soil temperatures for White Lake and Cass City (in the Thumb) by early March showed the soil was frozen (frost depth) down to at least a depth of four feet /48"/! Further south, around Detroit south into the Monroe and Lenawee Counties (at Tipton), the frost depth reached down to at least the 30 to 36" level. While there are no consistent records for years back, depths frozen down to around 40" in the immediate Detroit area seems to be a good estimate for lowest levels attained in that area (recorded in March of 1962).

Warmer weather returned mid month in time for Easter but at the same time, an approaching strong cold front churned up scattered severe thunderstorms Easter afternoon. Many reports of hail and high winds were received with the passage of these storms. Another Polar air mass made it far enough south into the Great Lakes to bring more snow showers to Southeast Lower Michigan on the 22nd (and hopefully the last of the season).

Specific Area Tallies

(note - new snow normals were used this winter)
 

The above comparative winter statistics really say it all when looking at this past winter and the huge contrast with the Winter of 2001-02. This past winter, Detroit's average temperature was nearly ten degrees colder than the Winter of 2001-02 and snowfall was nearly double! Not only were the two winters the inverse of each other in regard to temperature and snowfall, but both winters were also rather persistent with each of their perspective temperature trends, whether it cold or mild. Broadening the interval of time a bit, temperatures for each month of October through February 2001-02 averaged above normal, while averaging below normal for the October through February 2002-03 period. In fact, the last SIX months (Oct-Mar) at Detroit have now averaged below normal. The last time six straight months in a row averaged below normal was way back in 1979.

The expected dominant southern storm track through the Ohio Valley loaded up the Metro Detroit area with the most snow (and subsequent largest above normal departure) in all of Southeast Lower Michigan Snowfalls across extreme Southeast Lower Michigan from the Ohio State line northward to Detroit's furthest north suburbs averaged mainly between 50 and 65 inches with Metro Airport recording the 60.9 inches. The last time this much or more snow fell was back in the very snowy winter of 1981-82 (and the third snowiest winter on record) to find a winter with more snow /74.0"/ than this past winter. The 1977-78 winter in the winter study by far was the closest comparison for the 2002-03 snowfall with the two winter snowfalls nearly mirroring one another with 61.8 inches falling the winter of 1977-78 compared to the 60.9 this past winter (more on winter comparisons below).

Melted snowfall and rainfall left 2.24 inches of precipitation at Metro Airport in the rain bucket. Nearly all snow systems that moved through the area were rather dry and remember, the precipitation total only takes into account the winter months of Dec - Feb, whereas the snowfall total is through April. In any event, for the three month period, the 2.24 that fell made first place for driest winter on record. The old record for driest winter was 2.36 inches occurring back in another cold winter, 1962-63, with an average temperature of 20.4.

As might be expected, Flint's comparative winter statistics are nearly as extreme as Detroit's as far as temperatures with over nine degrees difference between the two winter averages. With an average temperature of just 22 � degrees, the Winter of 2002-03 was the 15th coldest winter on record. Contrast that with the Winter of 2001-02 with an average temperature of 31.7 degrees, resulting in the 2nd warmest winter on record, and the contrast is certainly exceptional.

Needless to say, several record lows were attained during the October through March period of 2002-03 with all but one month (Dec) averaging below normal. As was mentioned in Detroit, contrast that with the October through February 2001-02 period, in which all months averaged above normal). A total of six record lows were set this past winter (Dec-Feb time frame), while a total of 10 record lows were set in the October through March period.

Snowfall across the Flint area actually averaged below normal for a good part of the snow season, only catching up with, and then exceeding the normal during February and continuing into April as the virile storm track lifted northward a bit. Snowfall comparisons between the last two winters at Flint are not quite as dramatic, however, as Detroit, with just about a foot more this past winter. The winter of 1977-78, like Detroit, also proved to be nearly a mirror image as far as Flint's snowfall with nearly 51" /50.6/ .falling that winter compared to the 52" /52.1/ this past winter.

Melted snowfall and rainfall left 1.94 inches of precipitation at Flint Bishop Airport in the rain bucket. Nearly all snow systems that moved through the area were rather dry and the precipitation total is for the winter months of Dec - Feb, whereas the snowfall total is through April. In any event, for the three month period, the 1.94 that fell ranked this past winter as the third driest on record.

Like Detroit and Flint, Saginaw's winter temperature comparisons are outstanding. Saginaw's winter average temperature this past winter was the coldest of the three main cities. With an average temperature of just 21.3 degrees, this placed Saginaw in 19th place for coldest winter since 1900. This coming after the third warmest winter occurred the just the last winter.

Like nearby areas in the Saginaw Valley and Northern Thumb Region, Saginaw's snowfall held below normal. Of course, this was mainly due to the southern storm track that held south of this region. Even within the area of the Saginaw Valley into the Thumb Region snowfalls ranged some 15 to 20"!

Melted snowfall and rainfall left 2.17 inches of precipitation at the Saginaw Airport in the rain bucket. Nearly all snow systems that moved through the area were rather dry and the precipitation total is for the winter months of Dec - Feb, whereas the snowfall total is through April. In any event, for the three month period, the 2.17 that fell ranked this past winter as the sixth driest on record.