{"id":448,"date":"2017-03-02T17:42:24","date_gmt":"2017-03-02T16:42:24","guid":{"rendered":"http:\/\/blog.creamontblanc.org\/?p=448"},"modified":"2022-11-09T11:19:42","modified_gmt":"2022-11-09T10:19:42","slug":"soldes-dhiver-60-sur-les-precipitations","status":"publish","type":"post","link":"https:\/\/blog.creamontblanc.org?p=448","title":{"rendered":"SOLDES d’hiver : -60 % sur les pr\u00e9cipitations"},"content":{"rendered":"

[ENGLISH VERSION Below<\/em>] L\u2019hiver 2016-2017 a \u00e9t\u00e9 tr\u00e8s particulier dans la vall\u00e9e de Chamonix, tant au niveau des temp\u00e9ratures qui ont \u00e9t\u00e9 tr\u00e8s contrast\u00e9es, qu\u2019au niveau des pr\u00e9cipitations, largement d\u00e9ficitaires sur la p\u00e9riode. Soldes sur les pr\u00e9cipitations et neige brad\u00e9e, Geoffrey Klein, doctorant en climatologie, a men\u00e9 l\u2019enqu\u00eate. <\/strong><\/p>\n

\"Geoffrey<\/a>
Geoffrey Klein, doctorant en climatologie \u00e0 l’Universit\u00e9 de Neuchatel<\/em><\/figcaption><\/figure>\n

 <\/p>\n

Du gel et du yoyo pour les temp\u00e9ratures<\/strong><\/p>\n

L\u2019hiver 2016-2017 a \u00e9t\u00e9 marqu\u00e9 par une importante variabilit\u00e9 des temp\u00e9ratures de l\u2019air de mois en mois. Les mois de d\u00e9cembre et janvier ont connu de tr\u00e8s fr\u00e9quentes gel\u00e9es, dont notamment 61 jours cons\u00e9cutifs avec pr\u00e9sence de gel du 27 novembre au 26 janvier. Ces gel\u00e9es ont par ailleurs \u00e9t\u00e9 plus intenses que la moyenne bas\u00e9e sur la p\u00e9riode 1981-2010 : 51 jours de gel inf\u00e9rieur \u00e0 -5\u00b0 C sur la p\u00e9riode d\u00e9cembre-janvier contre 36 en moyenne. Ces conditions ont \u00e9t\u00e9 favoris\u00e9es par la pr\u00e9sence de longues p\u00e9riodes anticycloniques, apportant des nuits claires avec peu de vent et de l\u2019air froid venant majoritairement d\u2019Europe du Nord et de l\u2019Est.<\/p>\n

En revanche pour le mois de f\u00e9vrier, le nombre de jours de gel inf\u00e9rieur \u00e0 -5\u00b0 C a \u00e9t\u00e9 faible (5 contre 15 en moyenne), combin\u00e9 \u00e0 des temp\u00e9ratures maximales tr\u00e8s \u00e9lev\u00e9es pour la p\u00e9riode (9.4\u00b0 C contre 4.8\u00b0 C en moyenne). Cela a engendr\u00e9 un exc\u00e8s de temp\u00e9rature de pr\u00e8s de 5\u00b0 C par rapport la moyenne 1981-2010 pour ce mois de f\u00e9vrier (3.7\u00b0 C contre -0.8\u00b0 C en moyenne).<\/p>\n

Au final, la temp\u00e9rature moyenne de cet hiver \u00e0 Chamonix a \u00e9t\u00e9 1.3\u00b0 C plus \u00e9lev\u00e9e que la moyenne 1981-2010, en raison de temp\u00e9ratures maximales assez \u00e9lev\u00e9es qui ont compens\u00e9 les fr\u00e9quentes gel\u00e9es matinales.<\/p>\n

Des pr\u00e9cipitations 60 % inf\u00e9rieures \u00e0 la norme<\/strong><\/p>\n

Cet hiver a \u00e9t\u00e9 particuli\u00e8rement marqu\u00e9 par un important d\u00e9ficit de pr\u00e8s de 60% des pr\u00e9cipitations par rapport \u00e0 la moyenne de la p\u00e9riode 1981-2010, notamment sur le d\u00e9but de la saison o\u00f9 la vall\u00e9e de Chamonix n\u2019a pas connu la moindre pluie ou neige pendant 40 jours cons\u00e9cutifs, du 26 novembre au 5 janvier. L\u2019enneigement de la vall\u00e9e a ainsi \u00e9t\u00e9 directement impact\u00e9, avec une hauteur maximale de neige au sol de 35 cm relev\u00e9e \u00e0 Chamonix \u00e0 l\u2019observatoire du Mont-Blanc (contre 60 cm en moyenne sur les dix derniers hivers). Plus en altitude, la hauteur maximale de neige au sol a \u00e9galement \u00e9t\u00e9 tr\u00e8s faible, avec par exemple pas plus de 50 cm dans les aiguilles rouges (zone du Lac Blanc, 2330 m d\u2019altitude). D\u00e9but f\u00e9vrier, l\u2019\u00e9paisseur de neige au sol relev\u00e9e \u00e0 cet endroit \u00e9tait seulement de 5 cm.<\/p>\n

 <\/p>\n

R\u00e9daction : Geoffrey Klein<\/p>\n

\n

En savoir plus<\/strong><\/p>\n

L’enneigement des massifs en temps r\u00e9el<\/a> sur le site sports-hiver
\nNormales climatiques 1981-2010 \u00e0 Chamonix<\/a>, sur le site La m\u00e9t\u00e9o
\nDonn\u00e9es climatiques mensuelles \u00e0 Chamonix-Mont-Blanc<\/a> sur le site M\u00e9t\u00e9ociel<\/p>\n

\n

Newsletter<\/strong><\/p>\n

Pour suivre les activit\u00e9s du CREA Mont-Blanc et recevoir les articles scientifiques vulgaris\u00e9s, abonnez-vous <\/a>\u00e0 la newsletter du CREA Mont-Blanc<\/p>\n

 <\/p>\n

ENGLISH VERSION<\/strong><\/p>\n

 <\/p>\n

Winter Special: 60% off on precipitation<\/h1>\n

 <\/p>\n

In the Chamonix Valley, winter 2016-2017 has been a weird one.\u00a0\u00a0\u00a0 In terms of temperatures (which have been highly variable) and precipitation (which has been well-below average), this season has been a departure from the norm. Geoffrey Klein, PhD student in climatology working at CREA Mont-Blanc, brings us the story. <\/strong><\/p>\n

Freezing overnight and huge temperature swings:<\/strong><\/p>\n

Month after month, winter 2015-2017 has seen significant variability in air temperature.\u00a0\u00a0 Both the months of December and January were marked by frequent frosts\u2014including 61 consecutive days with below-freezing temperatures between November 27th and January 26th.\u00a0\u00a0 In addition, these frosts were more intense than the average established between 1981 and 2010:\u00a0 51 days in December and January had temperatures that fell below -5\u00b0C compared with an average of 36 days.\u00a0 These conditions were caused by long periods of high-pressure, clear nights, an absence of wind, and cold air coming from Northern and Eastern Europe.<\/p>\n

By contrast, during the month of February the number of days when the temperature dropped below -5\u00b0C was below normal (5 days vs. 15 on average) and maximum temperatures were also higher than usual (9.4\u00b0C vs. an average of 4.8\u00b0C).\u00a0 This meant that February temperatures exceeded the 1981-2010 average by nearly 5\u00b0C (3.7\u00b0C compared with an average of -0.8\u00b0C).<\/p>\n

Overall, the average temperature in Chamonix during the first few months of winter has been 1.3\u00b0C above the 1981-2010 average, with high daytime maximum temperatures compensating for frequent overnight frosts.<\/p>\n

Precipitation 60% below normal:<\/strong><\/p>\n

The biggest news this winter has been the drought, with precipitation levels at nearly 60% below the average for the period between 1981 and 2010.\u00a0\u00a0 At the beginning of the season, the Chamonix Valley didn\u2019t receive any snow or rain for 40 consecutive days, from November 26th to January 5th.\u00a0 Snow cover in the valley was directly impacted: the Mont Blanc Observatory in Chamonix recorded a maximum snow depth of 35cm, in contrast with an average of 60cm during the last ten years. At higher elevations, the maximum snow depth was also very low.\u00a0 In the Aiguilles Rouges (near Lac Blanc, at 2330m), the maximum snow depth was only 50cm, and in early February, there was only 5cm on the ground.<\/p>\n

Stay tuned to hear how the second half of the winter turns out.<\/p>\n

 <\/p>\n

Reported by Geoffrey Klein
\nTranslated by Hillary Gerardi<\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

[ENGLISH VERSION Below] L\u2019hiver 2016-2017 a \u00e9t\u00e9 tr\u00e8s particulier dans la vall\u00e9e de Chamonix, tant au niveau des temp\u00e9ratures qui ont \u00e9t\u00e9 tr\u00e8s contrast\u00e9es, qu\u2019au niveau des pr\u00e9cipitations, largement d\u00e9ficitaires sur la p\u00e9riode. Soldes sur les pr\u00e9cipitations et neige brad\u00e9e, … Lire la suite\u00ad\u00ad<\/a><\/p>\n","protected":false},"author":5,"featured_media":450,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"ngg_post_thumbnail":0,"footnotes":""},"categories":[194],"tags":[10,221,226],"class_list":["post-448","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-la-recherche","tag-climat","tag-enneigement","tag-temperature"],"aioseo_notices":[],"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/blog.creamontblanc.org\/index.php?rest_route=\/wp\/v2\/posts\/448","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.creamontblanc.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.creamontblanc.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.creamontblanc.org\/index.php?rest_route=\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.creamontblanc.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=448"}],"version-history":[{"count":7,"href":"https:\/\/blog.creamontblanc.org\/index.php?rest_route=\/wp\/v2\/posts\/448\/revisions"}],"predecessor-version":[{"id":864,"href":"https:\/\/blog.creamontblanc.org\/index.php?rest_route=\/wp\/v2\/posts\/448\/revisions\/864"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blog.creamontblanc.org\/index.php?rest_route=\/wp\/v2\/media\/450"}],"wp:attachment":[{"href":"https:\/\/blog.creamontblanc.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=448"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.creamontblanc.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=448"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.creamontblanc.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=448"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}